What are the dimenstions of `chi`, the magnetic susceptibility? Consider an H-atoms. Guess an expression for `chi`, upto a constant by constructing a quantity of dimenstions of `chi`, out of parameters of the atom: e, m, v, R and `mu_0`. Here, m is the electronic mass, v is the electronic velocity, R is Bohr radius. Estimate the number so obtained and compare with the value of `|chi|` ~ `10^-5` for many solid materials.