## E=hv

$E=hv$

Chase Yonamine 1J
Posts: 62
Joined: Fri Sep 28, 2018 12:17 am

### E=hv

In the equation, E=hv, does E represent the energy of the photon or does it represent the energy required to remove an electron?

anthony_trieu2L
Posts: 60
Joined: Fri Sep 28, 2018 12:29 am

### Re: E=hv

The value E represents the energy of the photon. However, you can use the equation E=hv to calculate the energy required to remove an electron after taking into account the kinetic energy. This works because the energy of the photon must be greater than or equal to the energy required to remove the electron.

Stevin1H
Posts: 89
Joined: Fri Sep 28, 2018 12:17 am

### Re: E=hv

E=hv represents the energy of the photon. However, it could also be equal to the energy required to remove an electron if the kinetic energy is 0. This is shown in the formula E(photon) - work function = Kinetic energy. If the Kinetic energy is 0, then the energy of the photon is equal to the work function.

haleyervin7
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### Re: E=hv

When it says we should be able to calculate the number of photons from this equation, we must have the total energy before we can do that, right?

sarahartzell1A
Posts: 56
Joined: Fri Sep 28, 2018 12:17 am

### Re: E=hv

E represents the energy of the photon but you can also use this equation to find the energy needed to remove the electron, just remember to pay attention to kinetic energy.

Jocelyne Milke 1G
Posts: 73
Joined: Fri Sep 28, 2018 12:25 am

### Re: E=hv

The work function is the energy needed to remove an electron.

Anmol_cheema_2F
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am

### Re: E=hv

E represents the energy of the photon, while the work function is the minimum energy needed to remove an electron.

KHuang1L
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### Re: E=hv

E is the energy of the photon. That equation is used to find the energy of a photon of light going at a certain speed. H is Planck's constant and v is the frequency of the electron. If E is equal to or greater than the threshold energy required to release an electron from an atom, then the electron is released.

Dayna Pham 1I
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Joined: Fri Sep 28, 2018 12:16 am
Been upvoted: 3 times

### Re: E=hv

E in this case is E(photon). The work function is the energy required to eject an electron in a 1:1 photon:electron interaction.

Keshav Bhatnagar 1H
Posts: 32
Joined: Fri Sep 28, 2018 12:17 am

### Re: E=hv

The E in E = hv represents the energy of a photon. The E in Ek = 1/2(mv^2) represents the excess energy after an electron is removed from a metal.

105085381
Posts: 44
Joined: Fri Sep 28, 2018 12:15 am

### Re: E=hv

I understand that...
Keshav Bhatnagar wrote:The E in E = hv represents the energy of a photon. The E in Ek = 1/2(mv^2) represents the excess energy after an electron is removed from a metal.

...but, can someone please clarify what the specific values are that we need to assign as hv and 1/2(mv^2)? Sorry if this was already stated!

Jayde Felix 4H
Posts: 59
Joined: Fri Sep 28, 2018 12:28 am

### Re: E=hv

Here, E would represent the energy of the photon

AlyssaBei_1F
Posts: 99
Joined: Fri Sep 28, 2018 12:17 am

### Re: E=hv

The E would represent the energy of the photon. The work function or threshold energy would be the energy required to remove an electron.

Cole Elsner 2J
Posts: 88
Joined: Fri Sep 28, 2018 12:25 am

### Re: E=hv

E represents the energy of the photon. h is Plancks's Constant (6.63*10^-34) and v is the calculated or measured frequency of a light source (typically UV or above for these equations)

Jack Hewitt 2H
Posts: 67
Joined: Fri Sep 28, 2018 12:27 am

### Re: E=hv

Chase Yonamine 1K wrote:In the equation, E=hv, does E represent the energy of the photon or does it represent the energy required to remove an electron?

e represents the energy of a photon. The works function represents the energy required to remove an electron.

jlinwashington1B
Posts: 65
Joined: Fri Sep 28, 2018 12:22 am

### Re: E=hv

I know that E represents the energy of the photon, while the equation itself represents electron removal... In lecture today Professor Lavelle showed us an example of the electron removal from a metal. My question is can electrons be removed anywhere?

David Zhang 1B
Posts: 48
Joined: Mon Jun 17, 2019 7:23 am

### Re: E=hv

The professor only mentioned metals when talking about the photoelectric effect. Can it happen to other materials as well?

Karolina herrera1F
Posts: 33
Joined: Sat Feb 02, 2019 12:15 am

### Re: E=hv

I don't think electrons can be removed from anymore I think there is more like a specific way in which it can be removed only. Maybe when it is jumping off the metal only?

Zachary Menz 1D
Posts: 32
Joined: Wed Nov 07, 2018 12:17 am

### Re: E=hv

E in E=hv represents the energy of a photon.

Daniel Kim 1D
Posts: 38
Joined: Wed Oct 03, 2018 12:17 am

### Re: E=hv

Represents the energy of the photon meanwhile the work function is the amount of energy needed to remove it.

Sisi Li 1F
Posts: 34
Joined: Mon Mar 11, 2019 12:15 am

### Re: E=hv

E is the energy of the photon. The work function, on the other hand, would give you the energy needed to remove an electron.

Michelle Xie 2B
Posts: 99
Joined: Sat Aug 17, 2019 12:18 am

### Re: E=hv

It represents the energy of a photon, but can be used to find energy needed.

Jasmine Summers 4G
Posts: 50
Joined: Wed Sep 18, 2019 12:17 am

### Re: E=hv

E represents the energy of a photon, and change in E can be used to find the difference in energy levels

Posts: 125
Joined: Sat Aug 17, 2019 12:17 am

### Re: E=hv

Keshav Bhatnagar 1H wrote:The E in E = hv represents the energy of a photon. The E in Ek = 1/2(mv^2) represents the excess energy after an electron is removed from a metal.

Just to clarify, if there is excess energy after the electron is ejected, that energy would be converted to kinetic energy (Ek). The v in the equation Ek=1/2(mv^2) refers to the velocity of the electron, correct? Because surely it is not referring to nu, as in E=hv.

alicechien_4F
Posts: 104
Joined: Sat Jul 20, 2019 12:15 am

### Re: E=hv

Nicholas_Gladkov_3H wrote:Just to clarify, if there is excess energy after the electron is ejected, that energy would be converted to kinetic energy (Ek). The v in the equation Ek=1/2(mv^2) refers to the velocity of the electron, correct? Because surely it is not referring to nu, as in E=hv.

Correct, the v refers to the velocity of the electron and not nu. This is because kinetic energy deals with objects in motion, so having v represent the velocity of a moving object makes sense in this context. Hope this helps clarify the difference!

Anish Patel 4B
Posts: 59
Joined: Thu Jul 11, 2019 12:17 am

### Re: E=hv

E=energy of photon
h=planck's constant (6.626 × 10-34 m^2*kg/s)
v=frequency in Hz

Brynne Burrows 3K
Posts: 52
Joined: Thu Jul 25, 2019 12:16 am

### Re: E=hv

E in this equation represents the energy of the photon. In some cases, it could also be equal to the energy required to remove an electron if the kinetic energy is 0. This is shown in the formula E(photon) - work function = Kinetic energy. If the Kinetic energy is 0, then the energy of the photon is equal to the work function.

Elizabeth 4I
Posts: 10
Joined: Fri Aug 02, 2019 12:16 am

### Re: E=hv

E represents the energy of a photon, however it also can be used to find energy that is needed.

205154661_Dis2J
Posts: 109
Joined: Wed Sep 18, 2019 12:21 am

### Re: E=hv

E in the equation represents energy but can also be used to find the energy needed to remove an electron!

305421980
Posts: 101
Joined: Sat Sep 07, 2019 12:16 am

### Re: E=hv

haleyervin7 wrote:When it says we should be able to calculate the number of photons from this equation, we must have the total energy before we can do that, right?

yes, it needs to b e calculated from the work function and kinetic energy values given

Kelsey Ash 1D
Posts: 50
Joined: Wed Sep 18, 2019 12:16 am

### Re: E=hv

E is supposed to represent the energy of a photon

Nyari Muchaka_Discussion 4A
Posts: 53
Joined: Thu Sep 19, 2019 12:17 am

### Re: E=hv

E=hv is to find the energy of a photon(light) and is usually coupled with the c=lambdaxvelocity because c represents the speed of light. When combined these two equations create the E=hc/lambda equation. If you want to find the energy contained in an electron, you would use the De Broglie equation as it is a different form of energy.

Heba Mengesha 3D
Posts: 50
Joined: Sat Sep 07, 2019 12:19 am

### Re: E=hv

E represents the energy (in joules) of the particle of light.

Joanne Lee 1J
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

### Re: E=hv

The E represents the amount of energy of a photon but you can always compare that E value to the work function value to determine whether the E amount is enough to remove the electron from one shell to another.

selatran1h
Posts: 52
Joined: Fri Aug 30, 2019 12:16 am

### Re: E=hv

E represents the energy of the photon while work represents the amount of energy it takes to remove the electron from the metal

Jialun Chen 4F
Posts: 108
Joined: Sat Sep 07, 2019 12:16 am

### Re: E=hv

E=hv is the incoming energy of electromagnetic radiation (photon). The energy needed to remove electron is the work function (represented by a greek alphabet).

PriscillaLi_3G
Posts: 63
Joined: Fri Sep 27, 2019 12:30 am

### Re: E=hv

E represents the energy of the photon.

Posts: 52
Joined: Thu Jul 11, 2019 12:16 am

### Re: E=hv

With this particle equation, E represents the energy of the photon.

Drew Myers 4G
Posts: 100
Joined: Sat Aug 17, 2019 12:17 am

### Re: E=hv

E represents the energy of the photon. The energy required to remove an electron is known as the work function/threshold energy and is not present in this equation.

kendal mccarthy
Posts: 109
Joined: Wed Nov 14, 2018 12:22 am

### Re: E=hv

E represents the energy of the photon, as it is the constant times the wavelength.

PriscillaLi_3G
Posts: 63
Joined: Fri Sep 27, 2019 12:30 am

### Re: E=hv

E represents the energy of one photon

jvera4b
Posts: 60
Joined: Wed Sep 11, 2019 12:17 am

### Re: E=hv

E is the energy of the photon and the work function is the threshold energy, the energy needed to remove an electron.

105289321
Posts: 49
Joined: Sat Sep 07, 2019 12:15 am

### Re: E=hv

E represents the energy of the photon, and it is the constant times the wavelength.

105289321
Posts: 49
Joined: Sat Sep 07, 2019 12:15 am

### Re: E=hv

E represents the energy of the photon, and it is the constant times the wavelength.