Question

Match the group with the valencies of the elements present in them.

• A. 2
• B. 1
• C. 3
• D. 0

Answer 1

If the number of electrons in the valence/outermost shell is:

• Less than or equal to four, then valency = Number of valence electrons
• Greater than 4, then valency = 8 - Number of valence electrons

Group number	Valence electrons	Valency
Group 1	1	1
Group 15	5	8-5=3
Group 18	8	8-8=0
Group 16	6	8-6=2