Which statement is always true about a reversible chemical reaction?

It is a chemical reaction in which the reactants form products and products react together to give reactants back. That means reversible reactions can go in both directions forward as well as backward direction.

is there multiple choice answers?

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.