Question

Q186) Among the following which one is not paramagnetic? [Atomic numbers; Be = 4, Ne = 10, As = 33, Cl = 17]

Q186) Among the following which one is not paramagnetic? [Atomic numbers; Be = 4, Ne = 10, As = 33, Cl = 17]

SOLUTION

Ne^{+2} = 8 = 1s^{2}, 2s^{2}, 2p^{4} = 1 unpaired electron
Be^{+1} = 3 = 1s^{2}, 2s = 1 unpaired electron
Cl^{–} = 18 = 1s^{2}, 2s^{2}, 2p^{6}, 3s^{2}, 3p^{6} = 0 unpaired electron
As^{+}= 32 = 1s^{2}, 2s^{2}, 2p^{6}, 3s^{2}, 3p^{6} 4s^{2}, 3d^{10}, 4p^{3} = 3 unpaired electron
If electrons are unpaired then it is not paramagnetic

Answer:(c)