Rate determining step

Question 1

Why is it unlikely for a reaction to occur in one step?

Answer 1

It is unlikely that 2 or more particles to collide with correct orientation and with enough activation energy

Question 2

What is the rate determining step?

Answer 2

The slowest step in a sequence of steps in a reaction
It includes the reacting species in the rate determining step
The orders of the reactants in the rate equation matches the rate determining step