## Energy change and Energy of photon

H-Atom ($E_{n}=-\frac{hR}{n^{2}}$)

Claire Lo 3C
Posts: 55
Joined: Sat Aug 17, 2019 12:18 am

### Energy change and Energy of photon

If a hydrogen atom goes from n=3 to n=1, why is the change in energy negative and why is the energy of the photon emitted positive?

Leyna Dang 2H
Posts: 104
Joined: Thu Jul 25, 2019 12:17 am

### Re: Energy change and Energy of photon

Going from a higher energy level to a lower, the change is negative, but photon energy is always positive, so if you set them equal to each other you would need a negative sign.

Ramneet Sandhu 3D
Posts: 50
Joined: Fri Aug 30, 2019 12:16 am

### Re: Energy change and Energy of photon

The change in energy would be negative because it is going from a higher energy state to a lower energy state. It is important to remember that only the change in energy can be negative, not energy itself.

Joelle 3L
Posts: 50
Joined: Sat Jul 20, 2019 12:16 am

### Re: Energy change and Energy of photon

The energy in a hydrogen atom depends on the energy of the electron. When you move from a higher state to a lower state, it decreases energy and the atom emits photons. The photon energy will always be positive.

Ally Huang- 1F
Posts: 103
Joined: Thu Jul 25, 2019 12:16 am

### Re: Energy change and Energy of photon

When atoms are going from a higher energy level to a lower energy level you would use the equation E(photon)=-deltaE, which always makes energy of the photon positive. When you have a negative change in energy it means light is emitted and the energy of the light emitted is always a positive number.

AveryAgosto
Posts: 76
Joined: Wed Sep 18, 2019 12:16 am

### Re: Energy change and Energy of photon

You cant have negative energy of a photon so just because the energy change is negative it doesn't mean you have negative energy.