The noble gases are sodal, nobble, leptum, and drogon. Among these gases nobble has the greatest atomic mass and sondal the least. Drogon is lighter than leptum.

The answer would be

In reversible reaction chemistry equilibrium is attained when the forward and reverse reactions are taking place at the same rate, thus, the concentrations of reactants and products remain the same. a reversible reaction is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back. in irreversible reactions on the other hand, the reactants react to form the products, which cannot revert back into reactants.