Energy of Light Light and electricity deliver energy in very different ways. Electricity has a basic unit called an electron. The basic unit contained in light is called a photon whose energy (E) is E = hν = hc/λ, where h (6.62x10-34) is the Planck’s constant, c is the speed of light (3x108), and ν and λ are the frequency and wavelength of light as an electromagnetic wave, respectively. Based on this equation, light with higher frequencies or shorter wavelengths will have more energy. Blue light has higher frequencies (shorter wavelengths) and therefore photons with higher energy, whereas red photons have less energy stored in them. Radio waves have very large wavelengths and therefore the least amount of energy, while gamma rays have tiny wavelengths and massive amounts of energy.

When scientist look at light they can split it up into various frequencies called spectrum. Using a device called spectroscope scientist can look at what makes up light and even figure out what elements where used to make the light. The spectroscope gives the wavelengths in 1,000 angstrom (Å) units, so the number you see is __x10-10m. Calculate the frequency and energy of at the 5 different spectrums that are found on the spectrum of helium light.

ν = λ · f E=hf = hc/λ

4471.48 Å à m à f= à E=

4713.14 Å à m à f= à E=

5015.67 Å à m à f= à E=

5875.62 Å à m à f= à E=

6678.15 Å à m à f= à E=

ShapeShape

ShapeShapeShapeenter image description here

List six parts of the electromagnetic spectrum other than visible light, and how they can be used.

Text Box