Question

Given below are the electronic configurations of some elements:

(a) 2,8,3

(b) 2,8,18,5

(c) 2,8,7

(d) 2,8,18,8,1

(e) 2,8,2

(f) 2,5

(g) 2,8,18,8

Answer the following:

(h) which elements belong to the same period?

Answer 1

The elements belonging to the same period are:

1. The elements in a periodic table extend horizontally from left to right.
2. The elements belonging to the same period have different properties.
3. They have same number of shells. On moving left to right in a period the number of valence electrons increases.
4. The elements having electronic configurations 2,8,3 and 2,8,7 and 2,8,2 belongs to the same period that is 3 and elements having electronic configurations 2,8,18,5 and 2,8,18,8 belong to same period that is 4.