Question

if element A and B as a atomic number 13 and 17 respectively
i)find the group number A and B
ii) period number of a and b
iii)formula between a and b

Answer 1

Answer:

Solution:-

Electronic configuration of element A with atomic no. 13 =2,8,3

Electronic configuration of element B with atomic no. 17=2,8,7

Electronic configuration of element C with atomic no. 20=2,8,8,2

Electronic configuration of element D with atomic no. 8=2,6

Valency of an element-

n for n≤4

8−n for n≥4

whereas, n = no. of electrons in outermost shell

1. Formula between element A and B-

Valency of element A=3(∵n≤4)

Valency of element B=8−7=1(∵n≥4)

∴ For formula between A and B- AB

3

2. Formula between element C and D-

Valency of element C=2(∵n≤4)

Valency of element B=8−6=2(∵n≥4)

∴ For formula between C and D- C

2

D

2

≡CD.