**Calculate the frequency of each of the following wave lengths of electromagnetic radiation.**

**1. 632.8 nm (wavelength of red light from helium-neon laser) ?**

**2. 503 nm (wavelength of maximum solar radiation) ?**

**3. 337.1 nm (wavelength of nitrogen laser) ?**

**Answer:**

c = ƒ x ?

where “c” is the speed of light in a vacuum in m/s, “ƒ” is the frequency in s^-1, and “?” is the wavelength in meters.

Part 1:

First, we must change the units of wavelength from nanometers to meters:

1 m = 10^-9 m

632.8 nm = 632.8 x 10^-9 m

c = 3.00 x 10^8 m/s

? = 632.8 x 10^-9 m

ƒ = ?

ƒ = c / ?

ƒ = (3.00 x 10^8 m/s) / (632.8 x 10^-9 m )

ƒ = 4.74 x 10^14 s^-1 or hertz

Answer: The frequency of maximum solar radiation whose wavelength is 632.8 nm is

ƒ = 4.74 x 10^14 s^-1 or hertz

Part 2:

First, we must change the units of wavelength from nanometers to meters:

1 m = 10^-9 m

503 nm = 503 x 10^-9 m = 5.03 x 10^-7 m

c = 3.00 x 10^8 m/s

? = 5.03 x 10^-7 m

ƒ = ?

ƒ = c / ?

ƒ = (3.00 x 10^8 m/s) / (5.03 x 10^-7 m)

ƒ = 5.98 x 10^14 s^-1 or hertz

Answer: The frequency of maximum solar radiation whose wavelength is 503 nm is

5.98 x 10^14 s^-1 or hertz.

Part 3

First, we must change the units of wavelength from nanometers to meters:

1 m = 10^-9 m

337.1 nm = 337.1 x 10^-9 m

c = 3.00 x 10^8 m/s

? = 337.1 x 10^-9 m

ƒ = ?

ƒ = c / ?

ƒ = (3.00 x 10^8 m/s) / (337.1 x 10^-9 m )

ƒ = 8.89 x 10^14 s^-1 or hertz

Answer: The frequency of maximum solar radiation whose wavelength is 337.1 nm is

8.89 x 10^14 s^-1 or hertz.