Answer
Avogadro’s law
Step-by-step explanation
Avogadro’s law
Avogadro's law states that, "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules." For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant.
Mathematical definition
The law can be written as:
V ∝ n or V/n = k
where
V is the volume of the gas;
n is the amount of substance of the gas (measured in moles);
k is a constant for a given temperature and pressure.