Question

The radius of first excited state of Be3+ ion???

Answer 1

$\huge{Hey Mate!!!}$

☆☞ Here is ur answer ☜☆

☆☞ 1/wavelength = RZ^2(1/1^2 - 1/infinity)
R is Rydberg constant. You can look that up in (in meters)
The term of 1/infinity will be zero.
This will give you wavelength and you can convert to energy with E = hc/wavelength.
Z is the atomic number of Be

HOPE IT HELPS.