Let , which is called the molar mass, stand for the mass of 1 mole of gas

Let μ, which is called the molar mass, stand for the mass of 1 mole of gas expressed in kilograms, so that it has the units of kg/mol, as opposed to M in the previous chapter, which has the units of kg/mol. Thus, for example, for the O₂ molecule μ is 32 × 10⁻³ kg/mol. Show that υ_rms = (3RT/μ)^1/2.