Question

15.Write the electronic configuration of following atoms/ions -
F
–

, Cr, Mg2+, O–

, Ca (Atomic number of F = 9, Cr = 24, Mg = 12 ,O = 8, Ca = 20)
​

Answer 1

Fluorine 1s^2s^2 2p^5 If it is fluoride 1s^2 2s^2 2p^6 (F^-1)

cr - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^4

Mg+2 1s^2 2s^2 2p^6 it losses 2electrons and become

Mg+2 (to form octet configuration in the outer most shell)

O- 1s^2 2s^2 2p^5 It gains one electron and become o-

ca: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2