Question

What 3 types of emission contribute to an overall emission spectrum?

Answer 1

Answer:

Most light sources can be classified into three main types: continuous, absorption, and emission. A hot, opaque object, like the filament in an incandescent light bulb, emits a continuous spectrum, having light of all wavelengths. A hot, dense gas is another example of an object that emits a continuous spectrum.

There are three types of spectra which an object can emit: continuous, emission and absorption spectra. The examples of these types of spectra shown below are for visible light as it is spread out from purple to red, but the concept is the same for any region of the electromagnetic spectrum.

Continuous spectra

Continuous spectra (also called a thermal or blackbody spectra) are emitted by any object that radiates heat (has a temperature). The light is spread out into a continuous band with every wavelength having some amount of radiation. For example, when sunlight is passed through a prism, it's light is spread out into it's colors.

Absorption spectra

If you look more closely at the Sun's spectrum, you will notice the presence of dark lines. These lines are caused by the Sun's atmosphere absorbing light at certain wavelengths, causing the intensity of the light at this wavelength to drop and appear dark. The atoms and molecules in a gas will absorb only certain wavelengths of light. The pattern of these lines is unique to each element and tells us what elements make up the atmosphere of the Sun. We usually see absorption spectra from regions in space where a cooler gas lies between us and a hotter source. We usually see absorption spectra from stars, planets with atmospheres, and galaxies.

Emission spectra

An emission spectra occurs when the atoms and molecules in a hot gas emit extra light at certain wavelengths, causing bright lines to appear in a spectra. As with absorption spectra, the pattern of these lines are unique for each element. We can see emission spectra from comets, nebula and certain types of stars.