Question

Two element A and B have atomic no.17 and 12 respectively. What will be their position in the periodic table?​

Answer 1

Explanation:

(i) Atomic no. of A - 17

Electronic configuration of A = 2, 8,7

Since it has '7' electrons in its outermost shell.

So, group to which A belongs = 10 +7 = group 17.

Period to which element A belongs = no. of shells = 3

So, period to which A belongs is 3rd

Atomic no. of B = 19

Electronic configuration of A = 2, 8, 8,1

Since it has 'l' electrons in its outermost shell.

So, group to which B belongs = group 1.

Period to which element B belongs = no. of shells = 4

So, period to which B belongs is 4th

(ii) Since, Valency of A = -1

Valency of B = +1

So, when A combines with B, the formula will be BA

(iii) The electron dot structure is as follows:

The bond formed between B and A is an ionic bond.

Answer 2

Answer:

Chlorine's atomic number is 17 and is located at 3rd period and 17th group of periodic table

AND

Magnesium's atomic number is 12 and is located at 3rd period and 2nd group