GENERAL KNOWLEDGE

Detailed explanation-1: -Groups are numbered 1–18 from left to right. The elements in group 1 are known as the alkali metals; those in group 2 are the alkaline earth metals; those in 15 are the pnictogens; those in 16 are the chalcogens; those in 17 are the halogens; and those in 18 are the noble gases.

Detailed explanation-2: -In chemistry, a group (also known as a family) is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table; the 14 f-block columns, between groups 2 and 3, are not numbered.

Detailed explanation-3: -Hence, there are 18 groups and 7 periods in the modern periodic table. And the atomic size and metallic character of elements increase down a group and decrease from left to right in a period.

Detailed explanation-4: -In the modern periodic table, there are 18 groups and 7 periods. Elements are arranged in rows and columns. The horizontal rows are known as periods while the vertical columns are known as groups.