Question

an element X has mass number = 35 and number of neutrons = 18 write atomic number and electronic configuration of X also write group number and period number and valency of x

Answer 1

The element X is chlorine. It's atomic number is 17. The electronic configuration of Cl is 2,8,7. It is placed in the 3 rd period.......

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Answer 2

Answer:

We know :

Atomic number = Mass number - No. of neutrons.

Atomic number = 35 - 18

= > 17

Electronic configuration :

2 , 8 , 7

Group no. = 17

Period no. = 3

Valency = - 1 .

Name of element is Chlorine (  Cl ) .