Question

State merits of long form of periodic table.

Answer 1

The long form of the periodic table is based on the modern periodic law according to which the physical and chemical properties of the elements are a periodic function of their atomic numbers.

• In this periodic table, elements are arranged in the increasing order of their atomic numbers.
• In the long form of the periodic table, there are 18 vertical columns called groups.
• There are 7 horizontal rows called periods.

Merits of a long form of the periodic table are as follows:

• Since the modern periodic table is based on the atomic number, it is easier to remember and makes the study more simplified than previous periodic tables.
• It correlates the electronic configuration of an element with its position in the periodic table.
• Based on the electronic configuration and valence electrons, elements are further classified into blocks like s, p, d and f which further aids in the study of the elements.
• It is a very logical arrangement as the elements are placed together on the basis of electronic configuration.
• It can explain the position of isotopes as this arrangement is based on atomic numbers rather than atomic masses.
• Three triads of 9 elements of the VIII^th group of Mendeleev's table are placed in 8^th, 9^th and 10^th groups in transition elements.
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