Final answer:
The CH3 free radical is sp2 hybridized due to its structure of three sigma bonds and an unpaired electron in a p orbital.
Step-by-step explanation:
The hybridization of the CH3 free radical involves the carbon atom having three sigma bonds and one unpaired electron. In this structure, the carbon atom is sp2 hybridized. This results from the combination of one s orbital and two p orbitals from the carbon atom to form three sp2 hybrid orbitals. The three hybrid orbitals form sigma bonds with the hydrogen atoms, and the remaining unhybridized p orbital contains the unpaired electron, characteristic of the free radical.
Reactive intermediates like the CH3 free radical are indeed short-lived, and they exhibit a tendency to react and form a stable configuration with a regular four bonds around the carbon atom. These free radicals participate in a series of reactions such as initiation, propagation, and termination within free radical reaction mechanisms.