An emission spectrum, an absorption spectrum, and a continuous spectrum are three different types of spectra that describe the distribution of electromagnetic radiation at various wavelengths. Let's define each of them:
Emission Spectrum: An emission spectrum refers to the range of wavelengths of electromagnetic radiation that is emitted by a particular source, such as an atom, molecule, or gas, when it is excited or energized. When these excited particles return to lower energy states, they release energy in the form of photons at specific wavelengths, which correspond to distinct colors or lines in the spectrum. The emission spectrum consists of these discrete, bright lines or bands of colors, representing the specific energies and transitions occurring within the emitting source. Each element or compound has a unique emission spectrum, which can be used to identify the composition of a substance or study its behavior.
Absorption Spectrum: An absorption spectrum, on the other hand, represents the wavelengths of electromagnetic radiation that are absorbed by a substance as it interacts with light passing through it. When light passes through a material, certain wavelengths are absorbed by the atoms or molecules within the substance, causing them to undergo electronic transitions or vibrations. The absorption spectrum is characterized by dark lines or bands at specific wavelengths, corresponding to the energies absorbed by the substance. These dark lines or bands indicate the missing or absorbed wavelengths from the continuous spectrum of light. Absorption spectra are often used in fields such as spectroscopy to analyze the composition and properties of materials.
Continuous Spectrum: A continuous spectrum, also known as a white light spectrum, is a spectrum that covers a broad range of wavelengths without any gaps or significant variations. It represents a smooth, uninterrupted distribution of electromagnetic radiation across a wide range of wavelengths. White light, such as sunlight or light from an incandescent bulb, is an example of a continuous spectrum. It contains all the visible colors blended together in a seamless manner, ranging from violet to red, without any distinct lines or bands. The continuous spectrum is not associated with any specific emission or absorption features but represents a continuous flow of electromagnetic energy.
In summary, an emission spectrum shows the specific wavelengths emitted by an excited source, an absorption spectrum displays the wavelengths absorbed by a material, and a continuous spectrum refers to a smooth and uninterrupted distribution of radiation across a wide range of wavelengths.