Why does a higher concentration make a reaction faster?

There are more collisions per second and the collisions are of greater energy.

Collisions occur with greater energy.

There are more collisions per second.

The answer is A -  There are more collisions per second and the collisions are of greater energy.

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).