Question

When hydrogen atom is in its first excited level, its radius is how many time its ground state radius?

Options

• half

• same

• twice

• four times

Answer 1

four times

Explanation:

For ground state, n = 1

For first excited state, n = 2

`"As  r"_"n" prop "n"^2`

`therefore  "radius becomes 4 times."`