# What alkyl group is CH2?

A methylene-bridge carbon is often seen within alkyl chains, i.e. as $\text{R"-"CH"_2-"R} '$.
in which case it is $s {p}^{3}$-hybridized. You might also see ${\text{CH}}_{2}$ depicted as this:
in which case it is called a methylene group. That is an $s {p}^{2}$ carbon.