Calculate the formula mass of sodium carbonate heptahydrate, Na, Co, -760, in atomic mass units (amu or u).

Agas diffuses 1/7 times faster than hydrogen gas (h2). what is the molar mass of the gas? 100.10 g/mol 98.78 g/mol 86.68 g/mol 79.98 g/mol

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as

Harry lives in a city, and he has a lung condition known as asthma. on certain days, harry has to stay inside because pollutants in the air make it difficult for him to breathe. which of these pollution sources are nonpoint sources that might bother harry if he goes outside? choose the two that apply.