The reaction above is

The equation shows propane (\(C_3H_8\)) reacting with chlorine gas (\(Cl_2\)) in the presence of ultraviolet light to produce chloropropane (\(C_3H_7Cl\)) and hydrogen chloride (\(HCl\)).

In this reaction, a hydrogen atom on the propane molecule is replaced by a chlorine atom. This is the hallmark of a substitution reaction, specifically a free-radical substitution. The UV light provides the energy needed to break the \(Cl-Cl\) bond homolytically, generating chlorine free radicals that then attack the alkane.

It is not neutralization (no acid-base reaction), not polymerization (no repeating monomer units are joined), and not oxidation in the classical sense used here. The defining feature is the direct replacement of one atom (H) by another (Cl) in the organic molecule.