Question

The formula of the product formed when the element A (atomic number 19) combines with the element B (atomic number 17), is:

• A. $AB$
• B. $A_{2}B$
• C. $A_2{B}_2$
• D. $A_2{B}_3$

Answer 1

The correct option is A $AB$

$K-1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^1$
$Cl-1s^{2}2s^{2}2p^{6}3s^{2}3p^5$
The above are the electronic configuration for 19 and 17 respectively.Potassium can donate 1 electron to get octet configuration where as Chlorine can accept one electron to get octet configuration.Hence it is an ionic bond and electron dot structure is as per given in the hint.