A perfect gas undergoes a reversible adiabatic expansion from (300 K,200 atm) to (90 K,10 atm). Find the atomicity of gas.

For reversible adiabatic processP11−γ⋅T1γ=P21−γ⋅T2γT1T2=P2P11−γγ;30090=102001−γγ103=1201−γγ;log⁡103=1−γx⋅log⁡1201−γγ=0.5229−1.301=−0.41γ=0.6⇒γ=1.66Atomicity =1