Question

2. How many oxygen atoms are indicated on the right side
of this balanced chemical equation?
4 Cr(s) + 3 O2( g)h2 Cr2O3( g)

Answer 1

What you have written in not a balanced chemical reaction.
Where is the arrow (->) ?
An arrow must separate the two sides of the reaction.
What is h2?
Cr2O3 is not a gas