Foundation
Chemistry
Electronic Configuration
Question

The number of d- electrons in Fe3+ is equal to that of :

d-electrons in Co+3

total s-electron in Na

p-electrons in N

total p-electrons in O–

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Solution

Fe3+ = [Ar] 4s0 3d5                Na = 1s2 2s2 2p6 3s1
    N = 1s2 2s2 2p3                 O¯ = 1s2 2s2 2p5