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?

The radius of the innermost orbit of a hydrogen atom, r1 = 5.3 × 10−11 m.

Let r2 be the radius of the orbit at n = 2. It is related to the radius of the innermost orbit as:

r2 = (n)² r1
= 4 × 5.3 × 10-11 = 2.12 × 10-10 m
For n = 3, we can write the corresponding electron radius as:

r3 = (n)² r1

= 9 × 5.3 x 10-11 = 4.77 × 10-10 m
Therefore, 2.12 × 10−10 m and 4.77 × 10−10 m are the radii of an electron for n = 2 and n = 3 orbits, respectively.