Consider two elements 'A' (Atomic number 17) and 'B' (Atomic number 19):

(i) Write the positions of these elements in the modern periodic table giving justification.

(ii) Write the formula of the compound formed when 'A' combines with 'B'.

(iii) Draw the electron dot structure of the compound and state the nature of the bond formed between the two elements.

(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 3^rd

Atomic no. of B = 19

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

Since it has '1' 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 4^th

(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.