Question

Order the relative rate of diffusion of the following gases from slowest to fastest, 1st being slowest, 6th being fastest.

1. Cl2
2. F2
3. He
4. Kr
5. N2
6. O2

5th
2nd
3rd
6th
1st
4th

Answer 1

@lyllian @NarWhalGod @ccowart22 @UsArmy3947 @mplatt

Answer 2

@Shadow @tigerlover

Answer 3

@JustSaiyan

Answer 4

This probably sounds a lot harder than it is. All it really takes is to know the molar mass of each gas. Lighter gases will diffuse faster than heavy gases, so really all you do is sort the weights:
C12: 12
F2: 37.9
He: 4
Kr: 83
N2: 14
O2: 15.9

So sort them from fastest to slowest (or largest to smallest):
Kr: 83
F2: 37.9
O2: 15.9
N2: 14
C12: 12
He: 4

Then just give them their places.
1. Cl2: fifth
2. F2: second
3. He: sixth
4. Kr: first
5. N2: fourth
6. O2: third

Answer 5

My mistake, you sort them from slowest to fastest. I did the sorting right, but labeled it wrong.

Answer 6

But the answer is still sorted correctly.