Question

.How the valency of an element can be determined from its electronic configuration?
Determine the valency of the element having an atomic number of 17.​

Answer 1

Answer:

valency of the element having atomic no 17 is 1

Explanation:

valency is combining capacity of an atom

as the atomic number is 17

its electronic coonfiguration is $1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{5}$

it has 7 electrons in its outer most shell

to obtain octet rule it should have 8 elctrons in its outer most shell

here there are 7 electrons.to obtain octet rule it should get 1 electron

it is its valency.so valency of this element is 1