(4*pi(0.5)(6.0221409*10^23))*(2*1.67*10^(-27)/(2*pi(1.38*10^(-23)((300)))))^(3/2)

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.