Question

an atom contains 20 protons, 20 electrons ans 20 neutrons. Mention the follwing details of the atom by its electronic configuration,atomic number,mass numbers and valency

Answer 1

The electronic configuration of atom is 2 , 8 , 8, 2 . Atomic no of the atom is 20 mass number is 40 u and valency is 2.Hope it helps you

Answer 2

Atomic Number = No. of electron or proton = 20

Atomic mass = No. of epectron or proton + No. of neutron = 40

Atomic configuration according to K L M N 2, 8, 8, 2
and according to s p d f Ar 4s^2

Valency = 2