## anonymous one year ago according to Planck E = nhv where n is an integer (1,2,3,..) which i believe is the quanta number h is planck constant v is the frequency of the electromagnetic but according to Einstein E = hv why there is no n?

1. Abhisar

Einstein's equation is $$\sf E=mc^2$$

2. anonymous

i know but he also give the formula e=hv i don't know my book is confusing.

3. anonymous

but anyway my, true problem is : please follow this link https://books.google.com.tw/books?id=2OxrDtDaSqIC&pg=PA532&lpg=PA532&dq=an+excited+hydrogen+atom+falls+back+to+level+n+%3D+1&source=bl&ots=Bs1QOonRNA&sig=IW5zZTti_NBlI4eQ4g0XM1g72tc&hl=en&sa=X&ei=EMeGVamPDZLj8AX39IKIDQ&ved=0CB4Q6AEwAA#v=onepage&q=an%20excited%20hydrogen%20atom%20falls%20back%20to%20level%20n%20%3D%201&f=false as we calculated the change in energy, we undergo "e=hv" equation, what about the n? the electron goes from sublevel 6 to 1 i am concerned about the n value, why we ignore the n value? perhaps it is 1 but why it is 1? .

4. anonymous

@abhisar

5. Abhisar

I am not able to access the link. The correct formula is $$\sf E=nh\nu$$, if we are talking about the energy transaction of one electron then we take n=1 but if we are taking into account energy transaction of multiple electrons, say 5 electrons then we will take n=5.

6. Abhisar

In your case, I believe your book is talking about one electron which goes from level 6 to 1. I think you are getting confused because we also use n to represent shell no.

7. Abhisar

Similarly, if we are talking about light energy. Total energy is given by the formula $$\sf E=nh\nu$$ where n is the number of photons (quanta of light)

8. Abhisar

Is it clear now?

9. anonymous

so n is just the number of electron?

10. Abhisar

Yes

11. anonymous

hmm.. gotta need a bit time to consider this. XD

12. anonymous

@Abhisar many says n is number of photons..

13. Abhisar

I don't want to confuse you, so just forget whatever I said above.

14. anonymous

okay

15. anonymous

so photons is basicly a magical thing that acts like particle but has no mass.

16. anonymous

lol i am going crazy

17. Abhisar

The formula to find the energy of one quanta/photon is $$\sf E=h\nu$$. Now the question is when do we use $$\sf E=nh\nu$$ then? It is used to find the total energy obtained from several quanta. Remember my flour bag example? Mass of one packet (quanta) was 1kg, if you transferred 5 packets (quanta) then total energy will be n$$\times$$ 1kg = 5kg. Similarly energy of one quanta is given by $$\sf E=h\nu$$, now if someone says find the total energy if n quanta are released then we use, $$\sf E=nh\nu$$

18. Abhisar

Clear?

19. anonymous

20. anonymous

anyway, thanks for helping me

21. anonymous

my book says "Einstein suggested that electromagnetic radiation can be viewed as a stream of "particles" now called photons. The energy of "each" photon is given by the expression e=hv i think the "each photon" mean n = photon... is photon quantized?

22. anonymous

i think the quanta thingy you mean is photon? is this true?

23. taramgrant0543664

E=hv is used when n=1, n is just the number of photons or quanta. It's just like in the ideal gas equation how PV=nRT the n represents the number of moles. n normally just represents the number of something. So E=nhv can be used to find the amount for more than one

24. Abhisar

$$\color{blue}{\text{Originally Posted by}}$$ @boen my book says "Einstein suggested that electromagnetic radiation can be viewed as a stream of "particles" now called photons. The energy of "each" photon is given by the expression e=hv i think the "each photon" mean n = photon... is photon quantized? $$\color{blue}{\text{End of Quote}}$$ Yes, Einstein suggested that besides the usual wave nature, light sometimes (while interacting with matter) shows particle nature and these particles are called as Photons or Quanta. These are quantized and can carry only a certain discrete amount of energy. this amount of energy is given by $$\sf E=h\nu$$. As a matter of fact you can also find the mass of these photons by using the equation $$\sf E=mc^2$$

25. anonymous

@abhisar I think you mean the energy of photon can be converted into mass.. E=mc2

26. anonymous

@abhisar not the photon contain mass because it is just a pack of energy??

27. Abhisar
28. anonymous

@abhisar thank you so much, you helped me a lot.

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