Can someone give me a link where I can find data on the size of an H atom (free and in main compounds like water)? If there is none can you tell me roughly the range of sizes or at least what is the ratio between a free atom and a bound atom. I know that for a free atom the radius is not the Bohr radius anymore , and that there is a cloud of probability, can you tell me what is the radius where probability is 95%? If it is possible, I'd like to learn what is the official value of the magnetic field B of the ground state (1s), as on the web I found many contrasting values. I tried to calculate it myself and I got 1/8 Tesla, is that correct? I read also that angular moment in QM is 0, is it h/2pi in classical model? Thanks a lot for your help.