This is in context to my previous question-how many degrees of freedom are associated with 2 g helium? Actually this question was asked in our school examination,to which most of us answered as 3.But our teachers say that it would be 0.5*4*6.022*10^23..................shouldnt degrees of freedom be independent of mass???

Dear Pratik, 

Degrees of freedom is in how many different ways an object can move around. For a monoatomic He atom your answer of 3 is correct, but for 2g of Helium it is not. All the atoms of He in the sample are free to move in 3 different ways. In total the whole sample can "move" in 3*0.5 mol ways. So the correct answer should be 3*0.5*6.023*10²³.

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