The Periodic Table Of The Elements printable pdf download

02-3

CTIVITY

The Periodic Table of the Elements

Substances that contain only atoms with the same number of protons are called elements. The

Periodic Table lists all the known elements in order of their atomic number and in columns that

depend on similarities in their chemical and physical properties. The Periodic Table is a useful tool

for both students and professionals to identify the properties of the elements and understand the

properties of molecules.

EARNING

BJECTIVES

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Become familiar with the organization of the Periodic Table

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Appreciate both the diversity and commonalities in the chemical and physical properties of the

elements

UCCESS

RITERIA

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Identify groups and periods in the Periodic Table

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Use the Periodic Table to provide information about the elements

REREQUISITES

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Activity 02-1: Atoms, Isotopes and Ions

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Activity 02-2: Mass Spectrometry and Masses of Atoms

NFORMATION

Dmitri Mendeleev (1834 − 1907), a Russian scientist, constructed the ﬁ rst Periodic Table by listing

the elements in horizontal rows in order of increasing atomic mass. He started new rows whenever

necessary to place elements with similar properties in the same vertical column. Mendeleev found

that the correlations in properties between some elements in the columns were not perfect. These

observations led him to predict the existence of undiscovered elements and to wonder how the

table might be better organized. Later H.G.J. Moseley used x-ray spectra to reﬁ ne the ordering and

show that atomic numbers rather than atomic masses should be used to order the elements.

In the Periodic Table, elements with similar properties occur in vertical columns called groups.

Two numbering conventions are used to label the groups. The older convention numbers the groups

using Roman numerals I through VIII followed by a letter A or B; the other convention numbers

each column 1 through 18. The A groups are known as the main group elements. The B groups are

called the transition elements. The group numbers IA through VIIIA in the older convention tells

you how many valence electrons an element has. The valence electrons are the outer electrons that

are most important in determining the chemical bonding and other properties of the element.

The horizontal rows of the table are called periods, and are numbered 1 through 7 starting with the

row that only contains H and He.

The Periodic Table Of The Elements