What happens to electric PE as n increases in a hydrogen atom?

[utkarshakash]

Homework Statement

As one considers orbits with higher values of n in a hydrogen atom, the electric potential energy of the atom
a)increases
b)decreases
c)remains same
d)does not increase

Homework Equations

The Attempt at a Solution

Energy of the atom in nth energy level is -13.6z^2/n^2. As n increases E should decrease.

 

[ehild]

Energy of the atom in nth energy level is -13.6z^2/n^2. As n increases E should decrease.

Do you mean -13.6z^2/n^2 becomes more negative if n increases?


ehild

 

[utkarshakash]

Do you mean -13.6z^2/n^2 becomes more negative if n increases?


ehild

I'm assuming the question asks about magnitude. The magnitude will decrease but if we consider -ve sign it will increase. I'm really confused!

 

[ehild]

No, it is not about the magnitude. You know that the potential energy is defined by an arbitrary constant. You could count the potential energy from the ground level of the hydrogen. Would the energy decrease in the excited states? Higher values of n mean excited states of the atom.

ehild

 

[rwisz]

So, the correct answer is b) decreases. This is because as the electron moves further away from the nucleus in higher energy levels, the electric potential energy decreases due to the inverse square law of electric force. Therefore, as n increases, the electric potential energy of the atom decreases.