Question

page 314
electromagnetic waves are usually categorized by their _.
page 315
electromagnetic waves can also be categorized by their _.
when sunlight passes through a prism, a rainbow appears. what does this show?
a. sunlight is made of many colors with different wavelengths.
b. sunlight is only made of red light.
c. the prism adds color to sunlight.
d. sunlight loses all its energy in the prism.

Explanation:

When sunlight passes through a prism, it gets dispersed. This is because sunlight is a mixture of different - colored light waves (electromagnetic waves) with different wavelengths. Each color (violet, indigo, blue, green, yellow, orange, red) has a unique wavelength. A prism does not add color to sunlight (so option C is wrong). Sunlight is not only made of red light (option B is wrong) and it does not lose all its energy in the prism (option D is wrong as the light just gets refracted and dispersed).

Answer:

A. Sunlight is made of many colors with different wavelengths.