## Atomic Spectra Post-Module Assessment Q. 20 [ENDORSED]

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

William Lan 2l
Posts: 73
Joined: Fri Sep 29, 2017 7:07 am

### Atomic Spectra Post-Module Assessment Q. 20

20. If 1 million photons in the UV region are absorbed by a hydrogen gas sample how many electrons are excited to a higher energy level?

A) Zero
B) 500,000
C) 1
D) 1 Million

I put my answer as 1 because I thought hydrogen has only 1 electron. So how is the answer incorrect?

Katie Lam 1B
Posts: 52
Joined: Fri Sep 29, 2017 7:06 am

### Re: Atomic Spectra Post-Module Assessment Q. 20

Each photon excites an electron to a higher level, so 1 million photons excites 1 million electrons (there is more than one hydrogen atom in the sample).

Cassandra Mullen 1E
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Joined: Fri Sep 29, 2017 7:07 am
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### Re: Atomic Spectra Post-Module Assessment Q. 20  [ENDORSED]

Remember that this process happens at a 1:1 ratio, where one photon excites/interacts with one electron.