Question

Given below are the electronic configurations of some elements :
a) A-2,8,3 b) B-2,8,18, c) C-2,8,7 d) D-2,8,18,8,1
e) E-2,8,2 f) F-2,5 g) G-2,8,18,8
Answer the following:
i) Which elements belong to the same period?
Which elements belong to the same group?
Which element is the first element of period?
iv) Which is a halogen ?

Answer 1

Answer:

(i) A is the terminating member of 3rd period.

(ii) B belongs to group 2.

(iii) E is a halogen (Halogens have seven electrons in their outermost shell).

(iv) C is the first element of 5th period.

(v) D is an alkali metal (Alkali metals have only one electron in their outermost shell).