Question

The atomic numbers of three elements A, B and C are given below Element
Atomic number
A
5
B
7
C
10
(i) Which element belongs to group 18?
(ii) Which element belongs to group 15?
(iii) Which element belongs to group 13?
(iv) To which period/periods do these elements belong?

Answer 1

Answer:

Boron have the atomic number 5 (element A) and it belongs to group 13

Nitrogen have the atomic number 7 (element B) and it belongs to group 15

Neon have atomic number 10 ( element C) and it belongs to group 18

All of these elements belong to second period