Question

Two elements X and Y have atomic no. 11 and 17 .
a) write the electonic configuration of these elements.
b) to which period of the modern periodic table these elements belong?
c) which element is a metal and which element is a non-metal?

Answer 1

a)this are sodium, and chlorine

Na=2,8,1

Cl=2,8,7

2)sodium is in 3rd period and chlorine is in 3rd period

3)chlorine is nonmetal while sodium is metal