Question

an element X has was number 35 and number of neutrons is 18 identify the group number and period of x

Answer 1

Hye mate..
=========

Given,

An element 'X' has the atomic number 35

No. of neutrons present in it = 18

Since,

Atomic number of ' X '= 35

Electronic Configuration of 'X' = 2.8.18.7

Here we have,

Group no. of element 'X'= 17

( Since, there are 7 valance electrons )

And Period no. of element 'X' = 4

( Since, there are 4 shells in it )

Also,

The name of the element 'X' is Bromine, which is a halogen.

Hope this helps !!!

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

Name of element is Chlorine (  Cl ) .