Question

an element A had mass number 24 and contains 12 neutrons .what is valecy of A

Answer 1

Element A's mass number = 24

Mass number= No of protons + No of neutrons
24 = 12 + No of protons
No of protons= 12
No of protons = No of electrons
No of electrons = 12
Electronic Configuration
= 2,8,2
So it's valency will be 2.