What Are Three Ways Light Interacts With Matter?

Light interacts with matter through absorption, transmission and reflection. When light strikes the leaf of a plant, the leaf absorbs the light energy, and through the process of photosynthesis, transforms the energy into the food glucose. The leaf reflects the green wavelengths of visible light, giving it the green color.

When light passes into a suspension, it is possible for people to see reflection and transmission. Windows transmit light, brightening a room. However, if light rays strike dust particles in the air, the rays are reflected to the eyes.

The color of an item is due to the wavelengths of light it absorbs and those it reflects. Objects that do not absorb any wavelengths of light appear white. Those that absorb all wavelengths appear black. However, other colors require a combination of absorption and reflection. A red cup appears red because it absorbs all the wavelengths of the spectra other than red while reflecting red to the observer's eyes. Thus, color is only intrinsic to an item because it has a few atoms on the surface that absorb some of the light. The scientific name of these color-absorbing atoms is pigments. Any remnants of white light the pigments do not absorb reflect to the eyes.