Comparing Temperature and Kinetic Energy for He and O2

[jgens]

Homework Statement

If you have on mole of He atoms and one mole of O₂ and add the same amount of energy to both, which underges the greater change in temperature? In which case are the particles, on average, moving faster.

Homework Equations

N/A

The Attempt at a Solution

I reasoned that for the first problem He would undergo the greater change in temp. since it has fewer degrees of freedom and all the energy goes into random translational kinetic energy. For the second problem I reasoned that the He particles must be moving faster because the have more KE and are less massive than O₂ molecules. Would someone mind letting me know if my reasoning is correct? Thanks.

 

[Andrew Mason]

Homework Statement

If you have on mole of He atoms and one mole of O₂ and add the same amount of energy to both, which underges the greater change in temperature? In which case are the particles, on average, moving faster.

The Attempt at a Solution

I reasoned that for the first problem He would undergo the greater change in temp. since it has fewer degrees of freedom and all the energy goes into random translational kinetic energy. For the second problem I reasoned that the He particles must be moving faster because the have more KE and are less massive than O₂ molecules.

Right on both points if by "more KE" you mean "more translational KE". The O2 and He molecules each have the same amount of kinetic energy if the same amount of energy is added to each and if they are kept separate.

AM