_________ is an electron pair donar that reacts at centers of positive charge.

________ step in the sequence of elementary reactions determines the measured reaction rate.

_____ is the unit of rate constant.

_____ collision is one which occurs between molecules which possess enough energy to cross the energy barrier and which are properly oriented with respect to each other.

______ of a chemical reaction describes how fast the reactants are used up and products are formed.

___________ step which controls the rate at which any subsequent step can proceed.

_______ is the minimum total kinetic energy that molecules must bring to their collision for a chemical reaction to occur.

The activity of solid catalysts is often considerably increased in the presence of small quantities of certain substances. Such substances are known as

The molecularity of a reaction in which only one molecule of the reactant is involved is 1, such a reaction is said to be ___________.

__________ is a molecular fragment with an unpaired electron.