Silicon's electron configuration
is 1s2, 2s2, 2p2
We can see that there are 3 sub-shells in the p orbital, and
two electrons can occupy each shell. However, electrons do not just pair up in
these shells unless each sub-shell has an electron. There are 3 sub-shells in
the p level, so the 2 electrons in the p level are free to be in different
sub-shells.
To sum it up, Silicon
has 2 unpaired electrons.
