## 3b on Quantum Test

$c=\lambda v$

Samantha Chang 2K
Posts: 69
Joined: Fri Sep 28, 2018 12:17 am

### 3b on Quantum Test

3b) in the second experiment if the same threshold voltage is applied to the mercury lamp(that is now significantly contaminated by atoms with a higher threshold energy) what will happen to the intensity of the light emitted?
Will the intensity not be affected? I have a hard time conceptually grasping this concept and the reason why.

904936893
Posts: 62
Joined: Fri Sep 28, 2018 12:29 am

### Re: 3b on Quantum Test

The intensity of the light will decrease (i.e. the lamp will be dimmer). This is because there are now atoms that have a higher threshold energy in the lamp. So, the voltage energy being emitted is not sufficient enough to excite these atoms with a higher threshold energy, to the next energy level, and no light will be emitted from those atoms. Therefore the light will be dimmer.

405112316
Posts: 62
Joined: Fri Sep 28, 2018 12:17 am

### Re: 3b on Quantum Test

The speed does not change as intensity increases. Since photons have particle properties, they can only eject one electron at a time. Increasing intensity will only increase the amount of electrons ejected.