Effective collision

what happen when they don’t have enough energy to make the reaction happen?Basically nothing, this collision is said elastic because the energy is conserved and the two molecules just have their direction changed.

Also, there is many way to “help” a collision become effective like heating up the environement which will increase the molecule speed and thus increase his energy.

Another cool way of making an effective collision are catalyser which are substances that reduce the energy needed for a reaction to happen.