The addition of a catalyst to a chemical reaction provides an alternate pathway that

has lower activation energy

Explanation:

A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and convert to products.

Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.

plasma is the state of matter where the substance is ionized and has no definite shape or volume. the fact of being ionized makes the substance a good electrical conductor.