Question

If the radius of first electron orbit in hydrogen atom be r then the radius of the fourth orbit ill be ______.

Options

• r

• 9r

• 4r

• 16r

Answer 1

If the radius of first electron orbit in hydrogen atom be r then the radius of the fourth orbit ill be 16r.

Explanation:

Radius of hydrogen atom is given by

`"r"_"n" = "n"^2 "r"`

where n is orbit number `"r"_4` = 16r