Question

explain why group 17 elements are strong non metals while group 1 elements are strong metals.

Answer 1

Because group 17 elements have tendency to gain electrons to complete their octet and group 1 elements have tendency to lose electrons to complete their octet. So this is why they are differentiated in metals and non metals.

Answer 2

group 1 elements are strong metal because they can loose electron easily and group 17 elements can one electrin easily