In a tank full of oxygen, how many molecular diameters d (on average) does an oxygen molecule travel (at 1.00 atm and 21.0°C) before colliding with another O2 molecule? (The diameter of the O2 molecule is approximately 3.60 10-10 m.) >> I don't know why webassign is telling me this is wrong and I can't figure out what I'm doing wrong. I used this equation: l=1/[(2^.5)(pi)(d^2)(nsubv)] Since n subv is equal to N/V which is equal to P/kb*T, I got 2.49e25. Then I just plugged everything in... and got 1.43e7 and divided by the diameter to see how many times it would cross that distance... and I got 3.98e16 What did I do wrong??