Which of the following does not happen during a chemical change?

the identities of the substances change.
bonds are broken and new bonds are formed.
some atoms disappear as energy is released.
compounds are broken down and/or formed.

Ammonia and oxygen react to form nitrogen monoxide and water, like this: 4nh3 (g) + 5o2 (g) → 4no (g) + 6h2o (g) also, a chemist finds that at a certain temperature the equilibrium mixture of ammonia, oxygen, nitrogen monoxide, and water has the following composition: compound pressure at equilibrium nh3 65.1atm o2 31.3atm no 62.7atm h2o 65.8atm compound pressure at equilibrium nh3 65.3 atm o2 7.79 atm no 12.1 atm h2o 65.8 atm calculate the value of the equilibrium constant kp for this reaction. round your answer to 2 significant

Iron (3) oxide will decompose in the presence of hydrogen gas and heater to produced iron and digydrogen monoxide white a balanced chemical equation

Areaction is first order with respect to reactant x and second order with respect to reactant y. which statement describes the rate law for this reaction?