Intro chem help Visible light spectrum? and energy of photon? help

[nchin]

on a visible spectrum scale what are the numbers for the colors of ROYGBIV? for example is violet 400-500nm and red is 700-800nm? how about the other colors?

If the energy of a photon is 2.63 x 10^-19 J, how can we tell what color this is? i was looking at this electromagnetic spectrum and it doesn't help me much.
http://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html

help!

 

[SteamKing]

I don't know where you got your wavelength ranges for the different colors. Here are a couple of different references:

http://en.wikipedia.org/wiki/Visible_spectrum#Spectral_colors
http://www.giangrandi.ch/optics/spectrum/spectrum.shtml

As far as the energy of a photon is concerned, look up Planck's constant.

 

[nchin]

I don't know where you got your wavelength ranges for the different colors. Here are a couple of different references:

http://en.wikipedia.org/wiki/Visible_spectrum#Spectral_colors
http://www.giangrandi.ch/optics/spectrum/spectrum.shtml

As far as the energy of a photon is concerned, look up Planck's constant.

One of my homework ques ask what is the wave length of 755nm and the answer is red.
how is 755nm wavelength = red? the charts shows that red is only up to 700.

 

[Ygggdrasil]

How people refer to color is somewhat subjective. However, I would probably call 755 nm light infrared rather than red.

 

[DeeNos]

The visible light spectrum is a range of wavelengths of electromagnetic radiation that our eyes are able to detect. It is commonly represented as the colors of the rainbow, with red having the longest wavelength and violet having the shortest. The numbers for the colors of ROYGBIV on a visible spectrum scale are as follows:

- Red: 620-750nm
- Orange: 590-620nm
- Yellow: 570-590nm
- Green: 495-570nm
- Blue: 450-495nm
- Indigo: 420-450nm
- Violet: 380-420nm

The energy of a photon is directly related to its wavelength, with shorter wavelengths having higher energy. The equation E=hc/λ (where E is energy, h is Planck's constant, c is the speed of light, and λ is wavelength) can be used to calculate the energy of a photon. Therefore, the energy of a photon with a wavelength of 2.63 x 10^-19 J would fall in the violet or blue range of the visible light spectrum.

The electromagnetic spectrum in the link provided shows the entire range of electromagnetic radiation, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. The visible light spectrum is only a small portion of this spectrum, and it can be difficult to determine the color of a specific photon just by looking at the spectrum. However, using the equation mentioned above, we can calculate the energy and corresponding color of a photon. I hope this helps clarify the visible light spectrum and the energy of photons for you.