calculate the number of atoms in 50 dm^3 nitrogen gas.
it is simple to do, but you have to know the temperature and pressure.
Ideal Gas Equation
PV=nRT
n= PV/RT where n is number of moles
number of atoms *two atoms per N2 molecule*= Avagrado's number*PV/RT
where Pressure is in kpa, and T is in Kelvins.