Question #678ec

1 Answer
Mar 2, 2017

Element number 13 has 1 unpaired electron.

Explanation:

Since Z = 13Z=13, the electronic configuration of this element, which can be obtained using the principle of Aufbau, is 1s^2 2s^2 2p^6 3s^2 3p^11s22s22p63s23p1.
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That means that at the last level (the n = 3n=3 level) there will be two paired electrons in the 3s3s orbital and one solitary electron (and, therefore, necessarily unpaired) in one of the 3p3p orbitals (in any of them since all three are degenerate).