In an atom of hydrogen the orbit radius is given by the formula:
r = n² · α₀
where:
n = number of orbit = 15
α₀ = Bohr radius (innermost radius) = 0.529 Â
Since d = 2 · r, we can write:
d = n² · d₀
= 15² · 1.06
= 238.5 Â
Hence, the diameter of the fifteenth orbit of the hydrogen atom is 238.5 Â.