Wny do we use the unit light years

Most objects in space are so far away, that using a relatively small unit of distance

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).

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2