The best term that describes the reaction is addition polymerization
Explanation:
Polymerization is a process which small molecules, monomers, undergo a chemical reaction to form polymer chains. The two general types are: addition polymerization and condensation polymerization.
Addition polymerization occurs when monomers reacts by the opening of the double bond to form a long carbon chain. The reaction continues until the reactive intermediate is destroyed in a termination reaction. This is a major process of producing polymers such as: poly(ethene) and poly(propene). It process has three stages which are: initiation, propagation, and termination.
Since electrons cannot have the same set of quantum numbers, a maximum of two can be in the n = 1 level, and a third electron must reside in the higher-energy n = 2 level. If there are two electrons in the n = 1 level, their spins must be in opposite directions.