## 1A.9 Energy of Photon

Ying Yan 1F
Posts: 101
Joined: Fri Aug 02, 2019 12:16 am

### 1A.9 Energy of Photon

On question 1A.9 I understand that the key equation is C=(wavelength)(frequency), however the question also asks for the energy of photon, how do I calculate for that? Thank you!

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

### Re: 1A.9 Energy of Photon

E = hv

So after u calculate v from c=wavelength x frequency, u plug it into E=hv with h as Planck's constant

MMckinney_4H
Posts: 61
Joined: Sat Sep 28, 2019 12:16 am

### Re: 1A.9 Energy of Photon

The formula (Planck's Constant)(frequency)= (Energy) would be able to help you if you know the frequency. If not, use the formula (wavelength)(frequency)=(speed of light) then substitute.

AniP_2D
Posts: 95
Joined: Sat Aug 17, 2019 12:17 am

### Re: 1A.9 Energy of Photon

You would use Energy=(Planck's constant)*(frequency) to find the energy of the photon. If you do not have the value of frequency, you would use speed of light=(wavelength)*(frequency) to find frequency and then plug it into the equation for energy.

Juana Abana 1G
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Joined: Wed Sep 18, 2019 12:15 am

### Re: 1A.9 Energy of Photon

You would use the equation: E = hv

Shutong Hou_1F
Posts: 117
Joined: Sat Sep 14, 2019 12:17 am

### Re: 1A.9 Energy of Photon

In finding the energy of photons, we generally consider E = (Plank's constant) * (frequency) as the key equation. However, the equation c = (wavelength) * (frequency) is also important in a way that sometimes we only know the wavelength, rather than the expected frequency of photons. By utilizing E = (Plank's constant) * (frequency) and c = (wavelength) * (frequency) and substitution, we could derive that E = (Plank's constant) * (c) / (wavelength).

504939134
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

### Re: 1A.9 Energy of Photon

After you find the wavelength of the radiation, you then find the energy by using E=h*v, which is Plancks constant 6.626x10^-34J times frequency which is given. Hope this helps!

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

### Re: 1A.9 Energy of Photon

You can try to solve for the frequency and once you get that, use the formula E= (Plank's constant)*(frequency), or E=hv, in order to get the energy of the photon. If you are given the wavelength and not the frequency, you could use wavelength to find the frequency by using formula v (frequency) = speed of light (2.998*10^8m.s^-1) / wavelength and plug it into E=hv.

Andrea_Torres
Posts: 98
Joined: Sun Sep 15, 2019 12:15 am

### Re: 1A.9 Energy of Photon

To calculate for the energy you use the equation E=hv, h being Planck's constant.

JasonKwon_3k
Posts: 51
Joined: Thu Jul 11, 2019 12:16 am

### Re: 1A.9 Energy of Photon

The energy of an individual photon can be calculated by the equation E=hv, with h being Planck's constant. By calculating "E", you calculate the energy of ONE photon, that can be transfered.

Claire Stoecklein 1E
Posts: 49
Joined: Sat Jul 20, 2019 12:15 am

### Re: 1A.9 Energy of Photon

Some questions (it may even be the one in contention) ask for the the energy of a mole of photons, in which case you would then multiply Plancks constant by Avogadros number.

Cynthia Rodas 4H
Posts: 51
Joined: Wed Sep 18, 2019 12:21 am

### Re: 1A.9 Energy of Photon

This problem in particular requires the use of two equations:
c= (wavelength)(frequency)
E = hv

E represents the energy of a photon
h represents Planck's constant (6.626 x 10[/sup]-34[/sup] J * s)
v represents the frequency of radiation

Since the first and third parts of the problem provide you with the frequency, you can just plug it into E= hv to get the energy of the photon.
For the fourth part, you would simply find the frequency using c= (wavelength)(frequency) and then plug the frequency into the energy equation.

Amanda Ung 4D
Posts: 50
Joined: Thu Jul 25, 2019 12:17 am

### Re: 1A.9 Energy of Photon

E = hv --> E is the energy of the photon and you get it by multiplying Planck's constant (h) and the frequency (v)