Which statement describes a reaction at equilibrium?

1. The mass of the products must equal the mass of the reactants
2. The entropy of the reactants must equal the entropy of the products
3. The rate of formation of the products must equal the rate of formation of the reactants.
4. The number of moles of the reactants must equal the number of moles of the products.

(04.05 hc) analyze the given diagram of the carbon cycle below. part 1: which compound does c represent? part 2: name a process that could release this compound into the air. part 3: explain how the elements that form it are conserved during the carbon cycle. use complete sentences to explain your answer. justify how this compound was created from a recycling of carbon in the carbon cycle. use complete sentences to explain your answer.