How much energy is required to ionize hydrogen when it is in the n = 5 state?

0.544 eV

Explanation:

To ionize the hydrogen atom

So the required energy is as  

So

We have to calculate the energy required to ionize hydrogen atom when it is in n=5

So the energy should be less than

the components of a vector are the parts of the vectors that are to each other.

b perpendicular