Question
( 3^{text {nd }} ) period grocyp ( underline{17} )
The element is chlorine
This is non-metal.
St can accept ie to have fully filled orbit. So, monovalent
Clectronic contiguration
( =1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5} rightarrow 1 a s+e 1 e c b r o )
So, hon-metal and monovalent

CD Element z is in third period and group 17 a of the period Table ras Is it a metal ay non - metal ? 262 what is the number of valency elections in its atom?
Solution
