Question

science class X periodic classification ​

Answer 1

Answer:

its chlorine.

Explanation:

Atomic number of X = Mass number of X – No. of neutrons

Atomic number of X = 35 - 18 = 17

Electronic configuration = 2, 8, 7

Group number = 17

Period Number = 3

Valency = 1

Answer 2

Explanation:

Atomic number= 17

Element name= Chlorine

Electronic configuration= 2,8,7

Group no.=17

Period no.= 3

Valency= 1