Test 2 final question  [ENDORSED]

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Tina Wen 1G
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Test 2 final question

Postby Tina Wen 1G » Fri Apr 27, 2018 2:39 pm

For the final question in test 2, how many electrons can 1 thousand photons of UV region send to higher energy levels? What is the quantitative relationship of energy transfer from photons to electrons?

princessturner1G
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Re: Test 2 final question  [ENDORSED]

Postby princessturner1G » Fri Apr 27, 2018 3:11 pm

It is 1 thousand electrons. 1 electron per one photon.

Elana Weingord 1C
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Re: Test 2 final question

Postby Elana Weingord 1C » Fri Apr 27, 2018 3:55 pm

there is always a one to one ration between the number of photons of light and the number of electrons that are ejected

Jennifer Tuell 1B
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Re: Test 2 final question

Postby Jennifer Tuell 1B » Fri Apr 27, 2018 5:08 pm

The test also mentioned that it was a UV light which is important to acknowledge because if it was a longer wavelength then no electrons would be ejected.

MadelynNguyen1F
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Re: Test 2 final question

Postby MadelynNguyen1F » Sat Apr 28, 2018 2:03 pm

It is a one to one ratio so 1000 electrons.

Alicia Beebe
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Re: Test 2 final question

Postby Alicia Beebe » Sun Apr 29, 2018 7:40 pm

I'm confused about the concept of photons versus energy. are photons the energy unit and therefore the more photons present the more electrons released? or are photons different from energy?

Hongtao Yao
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Re: Test 2 final question

Postby Hongtao Yao » Sun Apr 29, 2018 9:30 pm

Is there an explanation why the ratio is one to one or it's just a phenomenon that's being observed?

SamanthaGrohe1B
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Re: Test 2 final question

Postby SamanthaGrohe1B » Sun Apr 29, 2018 9:43 pm

So for this question are we just supposed to assume that the photons of UV light contain enough energy to overcome the threshold energy of the electrons?

Miya Lopez 1I
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Re: Test 2 final question

Postby Miya Lopez 1I » Sun Apr 29, 2018 10:38 pm

Alicia Beebe wrote:I'm confused about the concept of photons versus energy. are photons the energy unit and therefore the more photons present the more electrons released? or are photons different from energy?


I think photons *have* energy, but photons are not the energy unit (?). In the textbook it says, "It is important to note that the intensity of radiation is an indication of the number of photons present, whereas E=hv is a measure of the energy of each individual photon." (pg.12)

Surya Palavali 1D
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Re: Test 2 final question

Postby Surya Palavali 1D » Sun Apr 29, 2018 11:05 pm

From my understanding, photons are units of light. They have energy, but they are not energy per se.

Cindy Nguyen 1L
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Re: Test 2 final question

Postby Cindy Nguyen 1L » Mon Apr 30, 2018 7:13 am

In my version of the test, it was said that the photons were absorbed. That's why lines appear. Because we know this, it would mean the photons had the correct amount of energy in order to be excited to another energy level. It was given on the test that it had enough energy. We did not have to assume.

The relationship between energy and photons:

Recall Dr. Lavelle's diagram of different energy levels. n=1, n=2, n=3, and so on. The photons need to have a specific energy in order to eject electrons from the surface of the metal. For example, for an electron to get excited from n=1 to n=2, the photon that is shown onto this electron must have that amount of energy (the range from n=1 to n=2) in order for it to be excited. It can't have less energy than that or else it will not be excited. If it's excited from n=1 to n=3, it needs the exact amount of energy from n=1 to n=3. Each metal or conductive surface has different threshold energies. If a photon has more energy than is required for n=1 to n=2, than the extra energy is converted into kinetic energy.

The relationship between electrons and photons:

Because of the Photoelectric Effect Experiment, we are able to observe that photons have particle-like features as each photon (given enough energy) will emit one electron. It's a 1:1 ratio. This plays a role in the concept of wave-particle duality for light.

Alondra Juarez section 1E
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Re: Test 2 final question

Postby Alondra Juarez section 1E » Mon Apr 30, 2018 3:42 pm

it is a one to one ratio so it would be one thousand aswell.

Sara Veerman-1H
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Re: Test 2 final question

Postby Sara Veerman-1H » Mon Apr 30, 2018 4:10 pm

There is always a one-to-one ratio in the interactions between a photon and an electron, so when 1000 photons are used, 1000 electrons are emitted.

Allen Chen 1J
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Re: Test 2 final question

Postby Allen Chen 1J » Thu May 03, 2018 4:38 pm

Electrons and Photons have a 1-1 ratio so it would also be 1000

Johanna Caprietta 1E
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Re: Test 2 final question

Postby Johanna Caprietta 1E » Sun May 06, 2018 12:39 pm

I am still confused with this concept of one-to-one ratio. I was under the impression that this was releated to threshold.

Phil Timoteo 1K
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Re: Test 2 final question

Postby Phil Timoteo 1K » Sun May 06, 2018 2:34 pm

For every photon there is an electron. Which is why there would be 1000.


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