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The Wonders of the Periodic Table

Updated on August 11, 2015

Periodic Table

Periodic Table is the tabular arrangement of all the chemical elements which are organized based on atomic numbers, electronic configurations and existing chemical properties.
Periodic Table is the tabular arrangement of all the chemical elements which are organized based on atomic numbers, electronic configurations and existing chemical properties.

Objectives:

Upon completion of this lesson, the students should be able to:

1. list the characteristics of the modern periodic table

2. classify the elements in the periodic table

3. explain the periodicity of elements

explain the periodicity of elements

Johann Wolfgang Dobereiner classified the elements in groups of 3 called triads.
Johann Wolfgang Dobereiner classified the elements in groups of 3 called triads.
John A. Newlands arranged the elements in the order of increasing atomic mass.
John A. Newlands arranged the elements in the order of increasing atomic mass.
Lothar Meyerplotted a graph showing an attempt to group elements according to atomic weight.
Lothar Meyerplotted a graph showing an attempt to group elements according to atomic weight.
Dmitri Mendeleev arranged in the order of increasing atomic weights with a regular repetition (periodicity) of physical and chemical properties.
Dmitri Mendeleev arranged in the order of increasing atomic weights with a regular repetition (periodicity) of physical and chemical properties.
Henry Moseley is known for the Modern Periodic Law.
Henry Moseley is known for the Modern Periodic Law.

Development of Periodic Table

As early as 1800, chemists began to determine the atomic weights of some elements with fair accuracy. Several attempts were made to classify the elements on this basis.

1. Johann Wolfgang Dobereiner (1829)

He classified the elements in groups of 3 called triads, based on similarities in properties and that the atomic mass of the middle member of the triad was approximately the average of the atomic masses of the lightest elements.

2. John A. New Lands (1863)

He arranged the elements in the order of increasing atomic mass. The eight elements starting from a given one is a kind of repetition of the first like the eight notes of the octave of music and called it the law of octaves.

3. Lothar Meyer

He plotted a graph showing an attempt to group elements according to atomic weight.

4. Dmitri Mendeleyeev (1869)

He worked out a Periodic Table of Elements were the elements were arranged in the order of increasing atomic weights with a regular repetition (periodicity) of physical and chemical properties.

5. Henry Moseley (1887)

He arranged the elements in the order of increasing atomic numbers, which relates that the properties of the elements are periodic functions of their atomic numbers. This is known as the Modern Periodic Law.

What are periods, groups and families?

Periods are the 7 horizontal rows in the periodic table

  1. Period 1 has 2 elements corresponding to 2 electrons in the s sublevel.
  2. Periods 2 and 3 have 8 elements corresponding to 8 sublevel electrons in the s and p sublevels.
  3. Periods 4 and 5 have 18 elements corresponding to 18 electrons in the s,p and d sublevels.
  4. Periods 6 and 7 also include the 14 f electrons but the seventh period is incomplete.

Groups are the vertical columns in the periodic table, which are divided into A, and B subgroups. The A subgroups are often called families. Some of the A families are designated by the following:

a. Group IA - Alkali Metals

b. Group IIA - Alkaline Earth Metals

c. Group VIIA - Halogens

d. Group VIIIA - Noble Gases

Other A subgroups are classified according to the first element in the column:

a. Group IIIA - Boron Family

b. Group IVA - Carbon Family

c. Group VA - Nitrogen Family

d. Group VIA - Oxygen Family

Classification of Elements in the Periodic Table

1. Representative Elements are the elements in A Group/ Family. The term representative element is related to stepwise addition of electrons to the s and p sub levels of the atoms. Elements belonging to the same group or family have similar properties.

2. Noble Gases or Inert Gases are the elements in the last group with completely filled set of s and p orbitals.

3. Transition Elements are the elements in the columns IB - VIIIB which are called the B Group/Family. Take note that they start with IIB up to VIIB, which have 3 columns and then end with IB and IIB. These sequences, which contain 10 elements each, are related to the stepwise addition of the 10 electrons to the d sub level of the atoms. These elements are metallic-dense, lustrous, good conductor of heat and electricity and in the most cases are hard. They form the many colored compounds and form polyatomic ions like Mn04 and CrO4.

4. Inner Transition Elements are the 2 additional horizontal rows below composed of 2 groups of elements which were discovered to have similar characteristics as Lanthanum in the 6th period called Lathanoids (Rare Earth Metals) and Actinium (Heavy Rare Elements). The Lanthanoids are all metals while the Actinoids are all radioactive. All the elements after Uranium are produced artificially by nuclear reactions.

The Periodic Table and Electronic Configuration

The ground state electronic configuration of the element is related to their positions in the Modern Periodic Table.
The ground state electronic configuration of the element is related to their positions in the Modern Periodic Table.

The Concept of Valence

Elements within any group exhibit a characteristic valence. The alkali metals of group IA exhibit a valence of +1, since the atoms easily lose the one electron in the outer level. The halogen of Group VIIA has a valence of -1, since one electron is readily taken up. In general, atoms, which have less than 4 valence electron, tend to give up electron thus having a positive valence corresponding to the number of electrons lost. While atoms with more than 4 valence corresponding to the number of electrons gained.

Examples:

12 Mg 1s2 2s2 2p6 3s2

Magnesium will give up its 2 valence electrons forming a +2 valence

8 O 1s2 2s2 2p4

Oxygen has 6 valence electron thus it will gain 2 electrons -2 valence Group VIIIA has a stable outer configuration of electrons (with 8 valence electrons) and would not be expected to give up or take up electrons. Thus, this group has a zero valence.

In the B series, the incomplete level contributes to valence characteristics. One or two electrons from an incomplete inner level may be lost in chemical change and added to one or two electrons in the outer level, which allows possibilities of valence among the transition elements.

Examples:

26 Fe 1s2 2s2 2p6 3s2 3p6 4s2 3d6

Iron may exhibit valence of +2 by loss of the 2 outer electrons or a valence of +3 when additional electron is lost from the incomplete 3rd level.

Lewis Dot System: Kernel Notation and Electron Dot Notation

The kernel notation or electron dot notation is used to show the valence electrons in the atoms. The symbol of the elements is used to represent the nucleus and all inner electrons and dots are used for each of the valence electron.
The kernel notation or electron dot notation is used to show the valence electrons in the atoms. The symbol of the elements is used to represent the nucleus and all inner electrons and dots are used for each of the valence electron.

Metals, Nonmetals and Metalloids

Metals are at the left and in the center of the Periodic Table. About 80 elements are classified as metals including some form in every group except Groups VIIA and VIIIA. The atoms of metals tend to donate electrons.

Nonmetals are at the far right and toward the top of the Periodic Table. They are composed of about a dozen relatively common and important elements with the exception of Hydrogen. Atoms of non-metals tend to accept electrons.

Metalloids or borderline elements are elements that to some extent exhibit both metallic and nonmetallic properties. They usually act as electron donor with metals and electron acceptor with non-metals. These elements lie in the zigzag line in the Periodic Table.

Positions of metals, nonmetals and metalloids in the Periodic Table

Metals, nonmetals and metalloids are neatly arranged in the Periodic Table.
Metals, nonmetals and metalloids are neatly arranged in the Periodic Table.

Trends in the Periodic Table

Atomic Size

The atomic radius is approximately the distance of the outermost region of electron charge density in an atom drops off with increasing distance from the nucleus and approaches zero at a large distance. Therefore, there is no sharply defined boundary to determine the size of an isolated atom. The electron probability distribution is affected by neighboring atoms, hence, the size of an atom may change from one condition to another as in the formation of compounds, under different conditions. The size of the atomic radius is determined on covalently bonded particles of elements as they exist in nature or are in covalently bonded compounds.

Going across any period in the Periodic Table, there is a decrease in the size of the atomic radius. Going from left to right, the valence electron are all in the same energy level or the same general distance from the nucleus and that their nuclear charge increased by one. Nuclear charge is the force of attraction being offered by the nucleus towards electrons. Therefore, the greater the number of protons, the greater is the nuclear charge and the greater is the over pull of the nucleaus on the electron.

Examples:

Consider the atoms of Period 3:

Na 2e 8e 1e Mg 2e 8e 2e Al 2e 8e 3e

Consider the electronic configuration of Group IA elements:

Na 2e 8e 1e

K 2e 8e 8e 1e

Rb 2e 8e 18e 8e 1e

Cs 2e 8e 18e 18e 8e 1e

Fr 2e 8e 18e 18e 18e 8e 1e

Although the number of protons from top to bottom within the same group increases, the atomic size still increases due to the additional energy level as seen from the above illustration. Therefore, atomic size increases from top to bottom within the same group.

Atomic size and Periodic Table

Atoms get smaller from left to right in a period.
Atoms get smaller from left to right in a period.

Ionic Size

When an atom losses or gains electron, it becomes a positively/negatively charge particle called ion.

Examples:

Magnesium losses 2 electrons and becomes Mg+2 ion.

Oxygen gains 2 electrons and becomes 0-2 ion.

The loss of electrons by a metal atom results in a relatively large decrease in size, the radius of the ion formed is smaller than the radius of the atom from which it was formed. For nonmetals, when electrons are gained to form negative ions, there is a rather large increase in the size due to the repulsion of the electrons for one another.

Ionic size and Periodic Table

Cation and anion increase in size as you go down a group in a Periodic Table.
Cation and anion increase in size as you go down a group in a Periodic Table.

Ionization Energy

Ionization energy is the amount of energy required to remove the most loosely bound electron in a gaseous atom or ion to give a positive (+) particle of cation. The first ionization energy of an atom is the amount of energy required to remove the first valence electron from that atom. The second ionization energy of an atom is the amount of energy required to remove the second valence electron from the ion and so forth. The second ionization energy is always higher than the first, since an electron is removed from a positive ion, and the third is likewise higher than the second.

Going across a period, there is an increase in the ionization energy due to the removal of electron in each case is at the same level and there is a greater nuclear charge holding the electron.

Factors affecting the magnitude of the ionization potential:

  • The charge of the atomic nucleus for atoms of similar electronic arrangement. The greater the nuclear charge, the greater the ionization potential.
  • The shielding effect of inner electrons. The greater the shielding effect, the smaller the ionization potential.
  • The atomic radius. As the atomic size decreases in atoms with the same number of energy levels, the ionization potential increases.
  • The extent which the most loosely bound electron penetrates the cloud of inner electrons. The degree of penetration of electrons in a given main energy level decreases in the order of s>p>d>f. All other factors being equal, as in the given atom, it is harder to remove an (s) electron than a (p) electron, a p electron is harder than a (d) electron, and d electron is harder than an (f) electron.

Attractive force between the outer level electrons and the nucleus increases in proportion to the positive charge on the nucleus and decreases with respect to the distance separating the oppositely charged bodies. Outer electrons are not only attracted by the positive nucleus but are also repelled by electrons in the lower energy levels and their own level. This repulsion, which has the net result of reducing the affective nuclear charge, is called the shielding effect or screening effect. Since from top to bottom, ionization energy decreases in A family, the screening effect and distance factors must outweigh the importance of the increased charge of the nucleus.

Ionization Energy and Periodic Table

 Going across a period, there is an increase in the ionization energy due to the removal of electron in each case is at the same level and there is a greater nuclear charge holding the electron.
Going across a period, there is an increase in the ionization energy due to the removal of electron in each case is at the same level and there is a greater nuclear charge holding the electron.

Electron Affinity

Electron affinity is the energy given off when a neutral gaseous atom or ion takes in an electron. Negative ions or anions are formed. Determining electron affinities is a hard task; only those for the most nonmetallic elements have been evaluated. A second electron affinity values would involve gain and not loss of energy. An electron added to a negative ion would result in Coulombic repulsion.

Example:

0 + e- -------------- 0-1 -33 Kcal/mole

0 + e- -------------- 0-2 +189 Kcal/mole

This periodic trends of electron affinity, of the strongest nonmetals, the halogens, are due to their electron configuration, ns2 np5 that lack a p orbital to have stable gas configuration. Nonmetals tend to gain electrons to form negative ions than metals. Group VIIA has the highest electron affinity since only one electron is needed to complete a stable outer configuration of 8 electrons.

Electron Affinity and Periodic Table

Trends in Electron Affinity
Trends in Electron Affinity

Electronegativity

Electronegativity is the tendency of an atom to attract shared electrons to itself when it forms a chemical bond with another atom. Ionization potential and electron affinities are regarded as more or less expressions of electronegativities. Atoms with small size, high ionization potential and high electron affinities would be expected to have high electronegativities Atoms with orbitals nearly filled with electrons will have higher expected electronegativities than atoms with orbitals having few electrons.Non metals have higher electronegativities than metals. Metals are more of electron donors and non metals are electron acceptors. Electronegativity increases from left to right within a period and decreases from top to bottom within a group.

Electronegativity and Periodic Table

Electronegativity increases from left to right within a period and decreases from top to bottom within a group.
Electronegativity increases from left to right within a period and decreases from top to bottom within a group.

Summary of the Trends in the Periodic Table

Video on Periodic Table

Self - Progress Test

hypothetical Periodic Table
hypothetical Periodic Table

A. I. Based on the given IUPAC Periodic Table and hypothetical elements as positioned, answer the following:

1. The most metallic element.

2. The most nonmetallic element.

3. The element with the biggest atomic size.

4. The element/s classified as alkali metal/s.

5. The element/s classified as metalloids.

6. The element/s classified alkali-earth metals.

7. The transition element/s.

8. The element/s classified as halogens.

9. The lightest of the noble gas.

10. Element/s with electronic configuration/s ending in d.

11. Element/s with electronic configuration ending in f.

12. Element/s with two (2) valence electrons.

13. Element/s with six (6) valence electrons.

14. Element/s with eight (8) valence electrons.

15. Element/s with one main energy level.

II. Answer fully the following questions:

1. State the Periodic Law.

2. Explain clearly what is meant by the statement that the maximum possible number of electrons in the outermost energy level is eight.

3. What are transition elements? How do you account for the marked differences in their properties?

B. Copy and fill in the table below:

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    • Ronniel Legaspi profile image

      Ronniel Legaspi 3 months ago

      RONNIEL AERON R. LEGASPI BSEEC-3

      The periodic table organizes elements according to similar properties so you can tell the characteristics of an element just by looking at its position on the table and to distinguish what element we need to use in our lab.

    • gonzalesjabs profile image

      Javy Paul Gonzales 3 months ago from San Ildefonso Bulacan

      GONZALES, JAVY PAUL S. BSHM3

      Periodic table is very relevance to hospitality Management because it will give us an edge to distinguished nonmetal to metal and also we can know what possible element we can use to give our job an extra level like liquid nitrogen now use in cooking so periodic table is relevant to us.

    • profile image

      GONZALES, JAVY PAUL S. BSHM3 3 months ago

      Periodic table is very relevance to hospitality Management because it will give us an edge to distinguished nonmetal to metal and also we can know what possible element we can use to give our job an extra level like liquid nitrogen now use in cooking so periodic table is relevant to us.

    • profile image

      MJ Melencio 3 months ago

      Marc James Melencio

      Tourism

      General Chemistry

      T/F 7:30AM-12:00PM

      The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number (number of protons), electron configurations, and recurring chemical properties. This ordering shows periodic trends, such as elements with similar behaviour in the same column. It also shows four rectangular blocks with some approximately similar chemical properties

    • profile image

      Marc James Melencio 3 months ago

      Tourism

      General chemistry

      T/F 7:30am-12:00pm

      The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number (number of protons), electron configurations, and recurring chemical properties. This ordering shows periodic trends, such as elements with similar behaviour in the same column. It also shows four rectangular blocks with some approximately similar chemical properties

    • Jasper Sierto profile image

      Jasper Sierto 3 months ago

      Sierto Jasper L.

      The periodic table is a tabular arragement of the chemical elements, ordered bt their atomic number number (number of protons), electron configurations, and recurring chemical properties.

      As a Hospitality Management, we need to know this because we're on the service industry. We need to prioritize the safety of our client

    • profile image

      kenneth sanciangc 3 months ago

      Sanciangco Kenneth Philip H. BSHM

      The periodic table is organized like a guess in a hotel each elements is placed in a specific location or rooms because of its atomic structure. Each rows and column has specific characteristics like the different types of hotel rooms like single room,double room, queen bed etc. that may offer to the guest.

    • Rene Briane profile image

      Rene Briane 3 months ago

      Rene Briane G. Angeles

      BSEEC-III

      Periodic table of elements are very important to us all bacause it can be use in all things. to know all the elements that is existing in the world.

      It is helpful for engineers to know what is the best element that they can use by using periodic table of elements.

    • profile image

      Christine San Gabriel BSN1 3 months ago

      Periodic table is a table that show case of chemicals grouped together to understand its composition,and help us derive relationships between the elements.

    • profile image

      Danica Vipinoza 3 months ago

      For me, as a Hospitality Management Student it is important for us to know the different elements and and we can predict the types of chemical reactions that are likely for an element. We can work safely if we know about those components of those materials so we can properly use the materials we needed in our course.

    • Camille San Mateo profile image

      Camille San Mateo 3 months ago

      San Mateo, Camille C.

      BSN-1

      The periodic table organizeelement according to similar properties so you can tell the characteristics of an element just by looking at its position on the table. Those elements are important because we're surrounded by elements so that we need to know something behind of it. We need to know at least some of these especially the 13 elements in a human body; hydrogen, carbon, nitrogen, oxygen, sodium, magnesium, phosphorus, sulfur, chlorine, potassium, calcium, iron, iodine.

    • Jolina Gabriel profile image

      Jolina Gabriel 3 months ago

      JOLINA GABRIEL

      BSN-1

      the periodic table organizes elements to make nursing student easier to find. nurses might need them to know what drugs to use and students use them as a means of organization. its much easier to find the atomic mass of carbon by looking it up on the table as opposed to looking it up in a textbook.

    • davejshv profile image

      Dave Joshua Villangca 3 months ago

      Dave Joshua B. Villangca

      BSN-I

      Baliuag University

      General Chemistry

      T, F 7:30-12:00

      The Periodic Table is a tabular form wherein the elements are organized based on their atomic numbers and electron configuration. As a nursing student, it is important to know, memorize, and understand the 13 essential elements found in the Human Body- which are the carbon, hydrogen, oxygen, phosphorus, potassium, iodine, nitrogen, sulfur, calcium, iron, magnesium, sodium, and chlorine- in order for me to understand more how they function inside our body for us to become healthy and how we get disease when the elements are not in their usual set points. Understanding these elements can be a key to a door leading to a healthy and proper lifestyle.

    • profile image

      TORIBIO, PAULINE LOUISE A. 3 months ago

      TORIBIO, PAULINE LOUISE A.

      BSN1

      The Periodic Table is an organized list of elements. Everything around us is made up of chemicals. So basically we should know the importance of these elements in order for us to improve living.

      Learning the periodic table may not be easy but this is very applicable in every person and one's living.

      For a nursing student like me, the deeper explanation of elements such as their structure is worthy. The 13 basic components of the human body, their reactions to other elements or mixtures may help me discover or understand how a human body functions.

    • Bianca Bernardo profile image

      Bianca Bernardo 3 months ago

      Marucot, Katrina Bianca BSN 1 GEN CHEM 2017

      Understanding the periodic table is not only essential to the study of Nursing but is also very helpful. This serves as a guide to understanding different chemicals but the periodic table also shows us the elements different properties and how to properly combine them and use them. Through the periodic table, we better understand the essential elements in our daily lives such as Carbon, Oxygen, Hydrogen, Iron, Magnesium, Calcium, Phosporus, Zinc and many more which are essential to our bodies. The periodic table helps us further understand how to chemically combine different elements and how to separate them properly.

    • RussellBernardino profile image

      RussellBernardino 3 months ago

      RUSSELL BERNARDINO BSTM4. Periodic table helps provide , students like me, with an invaluable tool to quickly predict an element's properties, it's atomic mass, atomic number and what group it belongs to.

    • profile image

      Jahna Carmella B. Galvez 7 months ago

      Jahna Carmella B. Galvez

      BEED-II

      There are many reasons why the Periodic Table of Elements is important. The first and most important perhaps is that the elements are arranged by order of atomic number which allows scientists to clearly identify the properties of the elements. And also the periodic table organizes elements according to similar properties so you can tell the characteristics of an element just by looking at its position on the table. And as a future educator we should learn how to organize the class properly and systematically.

    • profile image

      Salvador, Jucel Roma M. 7 months ago

      The periodic table is the most important chemistry reference. Elements are arranged left to right and top to bottom in order of increasing atomic number. It generally coincides with increasing atomic mass. Using the data in the periodic table, students and others that are familiar with the periodic table can extract information concerning individual elements. Students also gain information from the periodic table by looking at how it is put together. By examining it, they will also be aware of the different elements and their groupings or classifications.

    • JosephineLopez04 profile image

      JosephineLopez04 7 months ago

      Josephine V. Lopez BEEd - II

      The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number (number of protons), electron configurations, and recurring chemical properties. This ordering shows periodic trends, such as elements with similar behaviour in the same column. It also shows four rectangular blocks with some approximately similar chemical properties. In general, within one row (period) the elements are metals on the left, and non-metals on the right.

      The rows of the table are called periods; the columns are called groups. Six groups have names as well as numbers: for example, group 17 elements are the halogens; and group 18, the noble gases. The periodic table can be used to derive relationships between the properties of the elements, and predict the properties of new elements yet to be discovered or synthesized. The periodic table provides a useful framework for analyzing chemical behaviour, and is widely used in chemistry and other sciences.

    • Cristina Perez profile image

      Cristina Perez 7 months ago

      Perez, Ma. Cristina M.

      BEED-II

      CAS 105/ tf/ 12:30-2:00

      The first and most important perhaps is that the elements are arranged by order of atomic number which allows scientists to clearly identify the properties of the elements. Scientific researchers agree that the periodic table is a master piece of organized chemical information.

      The periodic table is useful because it identifies and arranges all known elements in an informative manner. Elements are arranged into periods and families. The elements in each family or period may have similar or dissimilar physical and chemical properties.

      The periodic table arranges the elements into families and periods (vertical and horizontal rows). The elements in each family have similar properties. ... The table tells you what elements may have similar chemical and physical properties. The periodic table describes the atomic structure of all known elements.

    • Carmela Perez profile image

      Carmela Perez 7 months ago

      Perez, Ma. Carmela M.

      BEED-II

      (TF/ 12:30-2:00/ CAS 105)

      There are many reasons why the Periodic Table of Elements is important. The first and most important perhaps is that the elements are arranged by order of atomic number which allows scientists to clearly identify the properties of the elements. Scientific researchers agree that the periodic table is a master piece of organized chemical information. The progression of the periodic table into its current form is a major achievement in and of itself with contributions from many famous chemist and scientist. The modern periodic table has changed since Mendeleev's original table, yet both the first tables and the modern table are important for the same reason: The periodic table organizes elements according to similar properties so you can tell the characteristics of an element just by looking at its position on the table. he table is useful for modern students and scientists because it helps predict the types of chemical reactions that are likely for an element. Rather than memorize facts and figures for each element, a quick glance at the table reveals a lot about the reactivity of an element, whether it is likely to conduct electricity, whether it is hard or soft, and many other characteristics.

    • profile image

      Villaroman, Nikki D.C. BEEd III 7 months ago

      Periodic table of the elements, in chemistry, the organized array of all the chemical elements in order of increasing atomic number—i.e., the total number of protons in the atomic nucleus. When the chemical elements are thus arranged, there is a recurring pattern called the “periodic law” in their properties, in which elements in the same column (group) have similar properties. (See Figure 1.) The initial discovery, which was made by Dmitry I. Mendeleyev in the mid-19th century, has been of inestimable value in the development of chemistry.

      It was not actually recognized until the second decade of the 20th century that the order of elements in the periodic system is that of their atomic numbers, the integers of which are equal to the positive electrical charges of the atomic nuclei expressed in electronic units. In subsequent years great progress was made in explaining the periodic law in terms of the electronic structure of atoms and molecules. This clarification has increased the value of the law, which is used as much today as it was at the beginning of the 20th century, when it expressed the only known relationship among the elements.

    • Maniella de Leon profile image

      Maniella de Leon 7 months ago

      Periodic table is the most important tool in studying chemistry. It is the heart of chemistry. Without this, better understanding of chemistry would be impossible. or there would be no learning at all.

      In relation with teaching profession, The elements in the periodic table are our students. Teachers must know them well, know the capabilities of every student. because in teaching, the heart of it belongs to the students.

    • mariseperez08 profile image

      mariseperez08 7 months ago

      Perez, Nina Marise V.

      BEED-II

      TF-12:30-2:00pm/CAS 105

      The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number (number of protons), electron configurations, and recurring chemical properties. This ordering shows periodic trends, such as elements with similar behaviour in the same column. It also shows four rectangular blocks with some approximately similar chemical properties. In general, within one row (period) the elements are metals on the left, and non-metals on the right.

      The rows of the table are called periods; the columns are called groups. Six groups have names as well as numbers: for example, group 17 elements are the halogens; and group 18, the noble gases. The periodic table can be used to derive relationships between the properties of the elements, and predict the properties of new elements yet to be discovered or synthesized. The periodic table provides a useful framework for analyzing chemical behaviour, and is widely used in chemistry and other sciences.

      The Russian chemist Dmitri Mendeleev published the first widely recognized periodic table in 1869. He developed his table to illustrate periodic trends in the properties of the then-known elements. Mendeleev also predicted some properties of then-unknown elements that would be expected to fill gaps in this table. Most of his predictions were proved correct when the elements in question were subsequently discovered. Mendeleev's periodic table has since been expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behaviour.

      All elements from atomic numbers 1 (hydrogen) to 118 (oganesson) have been discovered or synthesized, with the most recent additions (nihonium, moscovium, tennessine, and oganesson) being confirmed by the IUPAC on December 30, 2015: they complete the first seven rows of the periodic table.[1][2] The first 94 elements exist naturally, although some are found only in trace amounts and were synthesized in laboratories before being found in nature.[n 1] Elements with atomic numbers from 95 to 118 have only been synthesized in laboratories or nuclear reactors.[3] Synthesis of elements having higher atomic numbers is being pursued. Numerous synthetic radionuclides of naturally occurring elements have also been produced in laboratories.

    • Maria Luz Mendoza profile image

      Maria Luz Mendoza 7 months ago

      MA. LUZ MENDOZA BEED II

      The Periodic Table of the Elements arranges all of the known elements in an informative array. Elements are arranged in order of increasing atomic number. Order generally coincides with increasing atomic mass. The periodic table is useful because it identifies and arranges all known elements in an informative manner. Elements are arranged into periods and families. The elements in each family or period may have similar or dissimilar physical and chemical properties. The periodic table is the most important chemistry reference there is. It arranges all the known elements in an informative array. Elements are arranged left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The elements on the periodic table is so important in life today, it has helped scientist discover so many big events. The periodic table helped scientist discover what elements were needed for humans to survive. The elements also help us discover our resources and what they need. Like plants and Animals need elements to grow. Like chlorine it helps animals digest food and humans, iron helps blood carry oxygen around the body and magnesium and chlorine to help plants convert the suns energy to food. Grass contains silica that makes it very strong. So, without discovery of the elements on the periodic table people wouldn’t know how to survive, there would be no healthy foods and money would not exist in life.

    • Elize Bantang 14 profile image

      Elize Bantang 14 7 months ago

      Eliza B. Merle BEEd-ll

      Periodic table of elements is the most important chemistry refence. It arranges all the known elements in an informative array. Elements are arranged left to right and top to bottom in order of increasing atomic number and coinsides with increasing atomic mass. The importance of the periodic table is that it provides a way of organizing the elements so that it's possible to make certain predictions about their chemical and physical properties based on their position in the table. With the help of periodic table, we can learn the properties of many elements at a time and classification of elements will be easier. For e.g. group 1A elements are metal, then we can figure out that all 7 elements i.e Hydrogen, Lithium, Sodium, Potassium, Rubidium, Cesium and Fracium are electro-positive in nature.

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      Karen Manalac, BAC IV 7:30-12:00 10 months ago

      The periodic table of elements is a tool that can be useful in such ways. Present in a periodic table of elements are the elements that are discovered and that exist in this world. It is important to be familiarize with that so that when there comes a time when you kind of encounter some elements, you may know a little bit of a background to that particular element. It it significant to our course due to the fact that we, researchers need to always dig on information that will be given to the people.

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      Chella Maniquiz, BSTM 7:30-12:00 10 months ago

      The periodic table is the most useful tool in chemistry. The periodic table was used to predict all the element on the table. It helps us know its atomic number and its atomic weight. Periodic table is also useful in our course Tourism or in Hospitality Management because it keep us to be aware in knowing what kind of elements when we prefer to work as a housekeeper in the future.

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      Nixie Miranda BAC II 10 months ago

      Periodic table is the most important chemistry reference. It arranges all the known elements in an informative array. Elements are arranged left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The Periodic Law states that the physical and chemical properties of the elements recur in a systematic and predictable way when the elements are arranged in order of increasing atomic number.

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      Mary joy Anoche BSA 1-2 21 months ago

      periodic table is not about presenting the name of the element, it show the atomic no or what that element consist, and there is an division with it. periodic table is important to us to learn what element is needed in chemical like the water its consist of two hydrogen and an oxygen.

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      John Ismael Espino Lozano 22 months ago from Baliuag Bulacan Philippines

      Lozano, John Ismael E. (BSA 1-2)

      For me periodic table is the list of all elements. Its is important because our body, everything, the world is made up of element. It has all the information of elements that needed on studies. It will be good if we all know each element in the periodic table

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      Kimberly Anne DC Magtalas 22 months ago

      Kimberly Anne DC. Magtalas BSA 1-3

      The periodic table of elements is important in science because everything is made up of elements. The periodic table is organized according to trends in element properties. The periodic table provides all the information you need to balance chemical reactions at a glance. It helps us predict the types of chemical reactions that are likely for an element. We can learn the properties of many elements at a time and classification of elements will be easier.

    • Rolaine Ingalla profile image

      Rolaine Ann Ingalla 22 months ago

      BSA 1-3 Ingalla, Rolaine Ann B.

    • Rolaine Ingalla profile image

      Rolaine Ann Ingalla 22 months ago

      A periodic table, a listing of chemical elements arranged according to their properties, can be similar to a chart of accounts, a listing of all accounts that are accompanied by their reference number, which can help the users to easy locate a specific element or an account title. Having enough knowledge on how the elements are located to their respective position now and how it will immediately locate can help us to be time efficient and, therefore, more works to finish and more pay in return.

    • Genie de Ocera profile image

      Genierose de Ocera 23 months ago from San Miguel, Bulacan

      Genierose de Ocera

      BSA I-4

      The periodic table of the elements has gone through numerous revisions over the years as scientists have gained more knowledge about the atomic structure of the elements. The most recent version of the periodic table provides useful information that, directly or indirectly, affects everyone.The periodic table is one of the most significant achievements in science, capturing the essence not only of chemistry but also of physics and biology. It is a unique tool, enabling scientists to predict the appearance and properties of matter on Earth and in the rest of the Universe. It gives a systematic account of the early developments that led to the classification of the elements. As an accountancy student who is taking up Science subjects, the table is useful for us including the scientists because it helps predict the types of chemical reactions that are likely for an element. Rather than memorize facts and figures for each element, a quick glance at the table reveals a lot about the re activity of an element, whether it is likely to conduct electricity, whether it is hard or soft, and many other characteristics.

    • Angelica Salinas profile image

      Angelica Salinas 23 months ago

      Angelica G. Salinas BSBA 1-1 - The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number (number of protons in the nucleus), electron configurations, and recurring chemical properties. The table also shows four rectangular blocks: s-, p- d- and f-block. In general, within one row (period) the elements are metals on the lefthand side, and non-metals on the righthand side. The rows of the table are called periods; the columns are called groups. Six groups (columns) have names as well as numbers: for example, group 17 elements are the halogens; and group 18, the noble gases. Dmitri Ivanovich Mendeleev was the one who formulated the Periodic Law, created his own version of the periodic table of elements, and used it to correct the properties of some already discovered elements and also to predict the properties of eight elements yet to be discovered.

    • Paulo Tomas profile image

      Paulo Tomas 2 years ago

      TOMAS J P BUHM

      A periodic table can help us to see all of the chemical symbol, mass, units etc. It can help us to study the chemical in easy way and it like a complete package you can see the definition of a specific chemical

    • Jole Ymenel Tila profile image

      Jole Ymenel Tila 2 years ago from Pulilan, Bulacan

      Tila Jole Ymenel F. BUHM

      The relevance of periodic table in Hospitality Management is it keeps us aware in knowing what kind of chemical element is compatible to another chemical element that would give satisfaction for a better product.

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      Rad Mesina 2 years ago from Calumpit, Bulacan

      23 MESINA, DJ BUHM

      The table is useful for modern students like us because it helps predict the types of chemical reactions that are likely for an element. Rather than memorize facts and figures for each element, a quick glance at the table reveals a lot about the reactivity of an element, whether it is likely to conduct electricity, whether it is hard or soft, and many other characteristics.

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      jairafulgencio 2 years ago

      FULGENCIO JM BUTM 2014

      It is important fro us to know how significant the periodic table in our course. As I have my own idea, for me, it is really important for us because we should know the components of every equipment and materials we are going to use

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      28quizon,CA 2 years ago

      as a tourism student it is very important to know the elements and components of periodic table so that we can understand what use of that element and substance.

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      Zyrine Mae Taruc 2 years ago

      Taruc, ZD, BUTM 2014

      Production of elements having higher atomic numbers is being pursued, with the question of how the periodic table may need to be modified to accommodate any such additions being a matter of ongoing debate.

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      MARCELO JME BUTM 2 years ago

      The periodic table is the most important chemistry reference there is. It arranges all the known elements in an informative array. Elements are arranged left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass.

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      Janice Gonzales 2 years ago

      GONZALES JB BUTM

      The important of periodic table is useful for modern students and scientists because it helps predict the types of chemical reactions that are likely for an element.

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      Mary Rose Banzon 2 years ago

      Periodic table was a main view in chemistry. When i was high school my teacher assigned us to memorized periodic table and now it is useful in my industry because of my gen. chemistry subject.

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      Mary Rose Banzon 2 years ago

      Being a TM student and an gen. chemistry student of prof liway the periodic table is important. even in high school our teacher is assigning us to memorized the periodic table and right now i think it is helpful in my subject.

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      Marife DG. Montejo 2 years ago

      The importance of studying and learning about the different elements in periodic table for us is to identify what elements is being used to create a certain thing. And what element is present on the thing we may used in the future to our job.

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      MarjorieLansanganBSHM 2 years ago

      The relevance of periodic table to us is to know how it was formed how is it arrange because in Hospitality Management we will handle several things that composes an element it is relevant because it will give us an edge to distinguished non metal to metal

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      19 Garcia R. BUHM 2 years ago

      A periodic tables are important to as because they can help to us to see all of the chemical symbol,mass,units etc. Being a HM students it is very important to know the elements and components of periodic tables.

    • Steph San profile image

      Steph San 2 years ago

      30SANTIAGO S, BUHM

      The periodic table of the elements has gone through numerous revisions over the years as scientists have gained more knowledge about the atomic structure of the elements. And periodic table help us to know what are the difference between all those element and it help us when preparing food because it teach us the differences between chemicals

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      Erwin pascual 2 years ago

      A periodic table can help us to see all of the chemical symbol, mass, units etc. It can help us to study the chemical in easy way and it like a complete package you can see the definition of a specific chemical

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      john angelo s. ortega bshm2 2 years ago

      as an hm student, it was very much important to know because in my industry, i need to know the different properties and substances of the chemicals we are using in cleaning specific part of the hotel . also as a cook, i need to know the different chemicals used in preparing or in making specific ingredients to make food.

    • Trisha Vanguardia profile image

      Patrisha Anne D.Vanguardia 2 years ago from San Ildefonso,Bulacan

      For HM student it is very important to know the elements and components of periodic table so that we can understand what use of that element and substance.

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      John Andrew Cabrera 2 years ago

      The periodic table is useful for modern students and scientists because it helps predict the types of chemical reactions that are likely for an element.

    • Glenric Samaniego profile image

      Glenric Samaniego 2 years ago

      This helps us understand and know the true nature of elements that we use everyday. Many of us does not know that we use elements as part of our daily living.

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      John Carlo Viola 2 years ago

      The relevance of the periodic table to HM students, it may help us and guide us to know what elements or substance we may use in cooking

    • Ellen Canoza profile image

      Ellen Mae M. Canoza 2 years ago from Bonga Mayor, Bustos Bulacan

      03, Canoza EM BUHM

      The relevance of Periodic Table in Hm students is a big scope for us,It's human nature to organize things. Cooks painstakingly organize their spices into various groupings, whether alphabetically or according to how often they're used. Kids dump out their piggy banks and sort their riches into piles of pe­nnies, nickels, dimes and quarters. Even the items in a grocery store are grouped a certain way.

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      Eimon Paolo 2 years ago

      Periodic table is very important because it is our guide in chemistry.

    • simplyariannejoy profile image

      simplyariannejoy 2 years ago

      17 Flores, AJ BUHM

      The relevance of periodic table in hospitality management is it keeps us aware in knowing what kind of chemical/element is compatible to another chemical/element that would give satisfaction for a better product.

    • renzocauzon profile image

      renzocauzon 2 years ago

      09 Cauzon,RA BUHM

      The periodic table is the most important chemistry reference there is. The periodic table is useful for modern students and scientists because it helps predict the types of chemical reactions that are likely for an element.

    • Rolyn Santos profile image

      Rolyn Santos 2 years ago from Bustos, Bulacan

      The periodic table is the most important chemistry reference there is. It arranges all the known elements is an inforamtive array. elements are arranged left to right and top to bottom is order of increasing atomis number. Order generally coincides with increasing atomic mass.

    • Richmond V profile image

      Richmond V 2 years ago from Bustos, Bulacan

      The periodic table is very important for students because it can help us on learning the basic characteristics of an element and the reactions it can create with other elements.

    • Krisette Enriquez profile image

      Krisette Enriquez 2 years ago from Plaridel, Bulacan

      13 ENRIQUEZ, KC BUTM 2014

      We, Tourism students, also need to learn about the Periodic table. It is helpful to identify a particular substance once we already know something about a certain element.

    • Patricia Rivera profile image

      Patricia Rivera 2 years ago

      In our case Periodic Table was really not my type in chemistry because it has many to study with, to be honest. But I really understand how to use it and the importance of it. In tourism management it can also be applied to my course and it helped me also by knowing the elements of it.

    • Cess Capulong profile image

      Cess Capulong 2 years ago

      It's a must to be able to understand and how, especially, use the periodic table. To specify the kind of elements. I remember when I was in high school the first element I learn is the Ca which is Calcium, well as for the other lessons periodic table is really useful for example: How to seek the atomic orbitals and such In total, things that we use, eat and see are things which involves the elements in the periodic table.

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      kennethCorpuz 2 years ago

      periodic table is a powerful and connect of the course because tourism management is needed of symbol nunber and names of periodic like carbon and oxygen is important of animals and palnts. about scientist is learn of cholesterol from animals and plants is phytosterol..

    • AlmiraEvangelista profile image

      AlmiraEvangelista 2 years ago

      Evangelista, Almira

      BSTM l-l

      When I first saw the periodic table, I had learn to use the periodic table at the hard way. I wasn’t sure how much it would help me, but when i started learning it, it made me realized that the elements in periodic table have much important in my field.

    • AndreaBarcita profile image

      AndreaBarcita 2 years ago

      3 BARCITA AR M. BUHM14

      The relevance of periodic table in our course is when we are cooking we check the ingredient if it is a liquid gas or solid. like in periodic table we check if its metal, metalloids or non metals and the different elements of this. It is important for us to know because if we don’t know, we might change something to that chemical or food

    • gelo hernandez profile image

      gelo hernandez 2 years ago

      Hernandez Angelo BSHM

      Periodic table is important because of it we will know the kinds of all metals, nonmetals and metalloids and also we can determine if it can harm us or not.

    • AndreaBarcita profile image

      AndreaBarcita 2 years ago

      3 BARCITA AR M. BUHM14

      The relevance of periodic table in our course is when we are cooking we check the ingredient if it is a liquid gas or solid. Like in periodic table we check if its metal, metalloids or non metals and the different elements of this. It is important for us to know because if we don’t know, we might change something to that chemical or food.

    • Cea Castillo profile image

      Cea Castillo 2 years ago

      The periodic table is useful for modern students and scientists because it helps predict the types of chemical reactions that are likely for an element. Rather than memorize facts and figures for each element, a quick glance at the table reveals a lot thing that you need.

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      Brillant Joshua Dela Cruz 2 years ago

      periodic table is the most important in science.

    • profile image

      Brillant Joshua Dela Cruz 2 years ago

      periodic table is the most important in science.

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      johnrenz santos 2 years ago

      24 SANTOS JRA BSHM14

      periodic table is the most important thing in the field of science.

    • Carl patrick tan profile image

      Carl patrick tan 2 years ago

      33 TAN BUHM

      Being a Hospitality Student, it is important fro us to know how significant the periodic table in our course. As I have my own idea, for me, it is really important for us because we should know the components of every equipment and materials we are going to use. Periodic table is used to learn about the elements; and in our course we are dealing with many kinds.

    • johncarl ballents profile image

      johncarl ballents 2 years ago from San Rafael, Bulacan

      Periodic table is important in hm. Because periodic Is Arrangement Of The Chemical Elements or the Basis Of Their Atomic Number.

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      Michael Baylon 2 years ago

      a table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns.

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      27 PARUNGAO GT BUTM 2015 2 years ago

      The periodic table is the most important chemistry reference there is. It arranges all the known elements in an informative array. People also gain information from the periodic table by looking at how it is put together. By examining an elements position on the periodic table, one can infer the electron configuration.

    • Joshua Lim Calma profile image

      Joshua Lim Calma 2 years ago from San Miguel Bulacan

      CALMA JOSHUA

      Periodic Table is 1 of most important because periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic number

    • Joshua Lim Calma profile image

      Joshua Lim Calma 2 years ago from San Miguel Bulacan

      CALMA JOSHUA

      The importance of periodic table to classified the kind of elements and they group and they uses.

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      HoneyGrace Salonga 2 years ago

      21 SALONGA HGC. BUHM14

      The importance of periodic Table is in we will classify it, if it is Metal,Non-Metal or Metalloids which is very important. we our living or sorrounded with different elements, that's why it gives as an idea when it is dangerous or not.

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      Johnmarverickr 2 years ago

      REYES, MARVERICK BUHM 2014-2015

      The significance of Periodic table in hospitality management is that the periodic table we use today is based on the one devised and published by Dmitri Mendeleev in 1869.Mendeleev realized that the table in front of him lay at the very heart of chemistry. And more than that, Mendeleev saw that his table was incomplete - there were spaces where elements should be, but no-one had discovered them.

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      Reniel Carillo 2 years ago

      periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic number (number of protons in the nucleus), electron configurations, and recurring chemical properties.

      CARILLO,RENIEL M. BUHM 2014-2015

    • Melanie Samson profile image

      Melanie Samson 2 years ago

      31 SAMSON, MH BUTM1-12014-2015

      Since the day I started my high-school year, Chemistry introduces me the periodic table and as I go through General Chemistry today, I supposed to study Periodic Table again and be able to know and learn the elements' properties and responsibilities.

    • Leah Mae Perez profile image

      Leah Mae Perez 2 years ago

      20 PEREZ, LME BUHM14

      As a HM student is very helpful to us because the periodic table will be the basic and to understand on how those elements reacts with each other to form compound. To be able to know the components of each elements and to differentiate the composition. It is also serve as a guide lines on how we can create on can make a proper mixture of elements.

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      john carl ballentes 2 years ago

      B A L L E N T E S, john B U H M 2014 2015

      periodic table are important to HM student,because in cooking we need to know what are the chemical that we use

    • Estacio M O BUTM profile image

      Estacio M O BUTM 2 years ago

      Estacio, M O BUTM - IRREG

      It is important specially in Tourism Industry because before you serve the food, you have to apply some ingredients that will make the food taste good.

    • Carla Katrina profile image

      Carla Katrina Liwag 2 years ago from Baliwag, Bulacan

      LIWAG, CK BUHM 2014

      Periodic table are important to HM students, because we use some elements when cooking, like aluminum for cans and foils, kitchen utensils. When we are cleaning, we should know what was the chemicals we need. Knowledge of this is useful for us.

    • Elli Rose Gabriel profile image

      Elli Rose Gabriel 2 years ago

      1 BALELA, E.G BUTM 2014

      We should know what are the periodic table's content and how it may affect the things that we are using to, specially as a Tourism student we're dealing with so many people. We should know what we're putting or using on preparing foods so it may not harm others.

    • Elli Rose Gabriel profile image

      Elli Rose Gabriel 2 years ago

      We should know what are the periodic table's content and how it may affect the things that we are using to, specially as a Tourism student we're dealing with so many people. We should know what we're putting or using on preparing foods so it may not harm others.

    • Pie Capistrano profile image

      Precious Alyssa Capistrano 2 years ago

      Periodic table of elements is important because it makes life easier. Instead of memorizing facts and figures for each element, a quick glance at the table reveals a lot about the reactivity of an element, whether it is likely to conduct electricity, whether it is hard or soft, and many other characteristics.

    • Clarenz Maximo profile image

      Clarenz Maximo 2 years ago

      21 MAXIMO CR BUTM 2014

      The importance of the periodic table is that it provides information about elements. We can easily know what element is it. Our field is dealing in many kinds of elements like foods and metal used in transportation so we really need to know many information about the elements.

    • Jonna Mae Book profile image

      Jonna Mae Book 2 years ago

      04 BOOK, JM BUTM 2014

      The importance of the periodic table is to know the atomic numbers, atomic mass, the valence, the electronegativity, and many more. Also to know the right chemical names. This is like a guide for us, some can memorize the periodic table but they prefer not to make it harder for some people so they create this in order not to be difficult. That's why this helps a lot.

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      RuelGiray 2 years ago

      13 Giray Ruel -BUTM 2014-2015

      The periodic table is useful for modern students and scientists because it helps predict the types of chemical reactions that are likely for an element.

    • Joanna Mari profile image

      Joanna Mari 2 years ago

      35 VERGEL DE DIOS, JMDC BUHM14

      In modern times, we have tripled our use of the elements, but we still fail to recognize their importance to our lives. The periodic table is our number one source of information on the elements, but it does little to highlight the elements all around us. Some information is inferred from looking at it in a certain way. But these properties can be abstract and difficult to understand.

    • Julien Villanueva profile image

      Julien Villanueva 2 years ago

      Villanueva, Julien / BUHM 2014-2015

      I don't get to use the periodic table a lot. But I still think that this is important. A lot of great people spend their lives making and revising the periodic table for us to gain knowledge about what they have discovered. Just imagine all of those elements. All of the details that we need to know about a certain element is in the periodic table. Imagine how much time and research they did for us to get all of the information we have right now. Periodic table is the fruit of their hard works. Periodic table is important.

    • yuriannesantos profile image

      yuriannesantos 2 years ago

      35 Santos YA BUTM 2014

      Periodic table is used to learn about the elements; and in our course we are dealing with many kinds.of elements like in foods, metals used in airplanes,buses,and many kinds of transportation so we need to know many informations about the elements.

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      Nicko Sanguyo 2 years ago

      28 NS BUHM

      Why we study the periodic table? It is bec. As a hm student we use any chemicals and that chemicals have an element. It is easy to us to classify what is that chemical are used for.

    • Agnes Sato profile image

      Agnes Sato 2 years ago from Baliuag, Bulacan

      36 SATO MA BSTM

      The periodic table of elements is important in my field, tourism management because there are meanings in each letters. And there are some mixing food and beverages in our field. There is also mettalic and non-metallic. Etc.

    • Ivory Salonga profile image

      Ivory Salonga 2 years ago from San Ildefonso, Bulacan

      32 salonga IS BSTM 2014

      Periodic table is very important in chemistry and also in my industry which is tourism industry because like when we are mixing foods and put a salt or a sugar it can taste good,i can know the chemicals And i can know the amount of salt and the important of it. Otherwise, the metal when we our on the airplane we can know if that is metal or metallic.