Q: The radius of the innermost electron orbit of a hydrogen atom is 5.3 × 10-11 m. what are the radii of
the n = 2 and n = 3 orbits ?
Sol: Given, the radius of the innermost electron orbit of a hydrogen r1 = 5.3 × 10-11 m
As we know that rn = n2 r1
For n = 2, radius r2 = 22 r1
r2 = 4 × 5.3 × 10^(-11) = 2.12 × 10-10 m.
For n = 3, radius r3 = 32 r1
r3 = 9 × 5.3 × 10-11 = 4.77 × 10-10 m.