Question

Match the elements in Column A to their respective valencies in column B:​

Column A	Column B
(a) K	(i) 4
(b) C	(ii) 2
(c) S	(iii) 1

• A. a: (i); b: (iii); c: (ii)​
• B. a: (iii); b: (i); c: (ii)​
• C. a: (iii); b: (ii); c: (i)​
• D. a: (ii); b: (i); c: (iii)​

Answer 1

The correct option is B a: (iii); b: (i); c: (ii)​

Number of electrons gained/lost/shared to attain the octet configuration is known as valency.

• K has 1 electron in its outermost shell. On losing that electron, it achieves a noble gas configuration. So valency of K is 1.
• C has 4 electrons in its outermost shell. On sharing those electrons, it achieves a noble gas configuration. So valency of C is 4.
• S has 6 electrons in its outermost shell. On gaining 2 more electrons, it achieves a noble gas configuration. So valency of S is 2.