Explain why, even though a collision may have energy in excess of the activation energy, what reaction may not occur ?

Activation energy is the energy needed to start a reaction, eg the flame needed to start ... Collisions may have enough energy to react yet not react if the orientation of the molecules is incorrect. Difficult to explain here without graphics, but basically of the molecules are facing the wrong way it won't happen.

is it a purebred? it looks more like a red nose, but it doesn't have the red could it be a staffordshire bull terrior? unsure if that's the right name for it sorry