Question

An element X has mass no. =35 and no. Of neutron =18 write atomic no. and electronic configuration of X.Also write group no., period no. And valency of X.

Answer 1

Hey friend!!!

Here's your answer..............

Atomic no.=Mass no.-no. of neutrons

=35-18

=17

Now it's time for electronic configuration...........

K shell=2 electrons

L shell=8 electrons

M shell=18 electrons

N shell=32 electrons

Then,its atomic no. is 17 = no. of electrons.......

K shell = 2

L shell = 8

M shell = 7

Now let's find valency............

Valency=1-

As, for an atom to became stable it requires 8 electrons and in last shell it has only 7 electrons so, it requires 1 electron to become stable and it will take one atom from some other molecule and will become stable...........

Then, valency will be 1-

The name of the atom is chlorine(Cl)

Hope it will help you............

Stay blessed.................