Hello there!
Let's explain to you the different variables in the PV=nRT equation:
PV=nRT:
P = Pressure
V = Volume
n = Moles (number of moles)
R = Gas Constant (universal)
T = Temperature
This is the ideal use of the gas law.
When calculating these different variables, its units are:
P = ATM (atmospheres)
V = L (liters)
n = mol (Moles)
R = J (Joule)
T= K (Kelvin)