A spectrum is defined as the characteristic wavelengths of electromagnetic radiation or a portion that is emitted or absorbed by an object, substance, atom, or molecule. Spectra helps identify the composition of substances and analyze various physical processes.
What are the Types of Spectrum?
Emission Spectrum
The spectrum produced by the radiation emitted when an electron in an atom or molecule transitions from a higher to a lower energy state. It represents the energy released during these transitions.
Subtypes of Emission Spectrum:
- Continuous Spectrum:
When sunlight passes through a prism, it disperses into a continuous band of colors without gaps. Similarly, light from an incandescent object forms a continuous spectrum when analyzed through a prism or spectroscope. - Line Spectrum (Atomic Spectrum):
When the radiation emitted by an excited substance is analyzed using a spectroscope, it produces distinct, bright lines of specific colors with dark spaces in between. This is unique to the element or compound, making it an important tool in identifying substances.
Absorption Spectrum
The spectrum is produced by the radiation a substance absorbs when light passes through it. It appears as dark lines or bands on a continuous spectrum background and helps analyze molecular composition.
Examples of Spectrum:
- The Rainbow
- Emission colors from the Sun
- Infrared absorption wavelengths from a molecule
Spectrum in Daily Life
- Rainbow: A natural example of the visible spectrum formed when sunlight passes through water droplets, splitting into its constituent colors.
- Sun’s Emission: The Sun emits radiation across a wide spectrum, including visible light and ultraviolet rays.
- Infrared Absorption: Molecules absorb infrared light at specific wavelengths, useful for analyzing their structure and bonding.
Explore More:
- How Does an Electric Motor Work?
- Why is the Bulb of a Thermometer Made of Thin Glass?
- Which is the Smallest Whole Number?
- What is Splitting of Light?
- Is Stone Rigid or Non-Rigid?
Applications of Spectra
- Astronomy: Helps identify the composition of stars and galaxies through spectral analysis.
- Medicine: Infrared and X-ray spectroscopy are used in diagnostics and imaging.
- Chemistry: Emission and absorption spectra are critical in identifying elements and molecules.
Interesting Facts about Spectrum
- The line spectrum is unique for every element, making it a “fingerprint” for identifying substances.
- Spectra helped discover elements like helium, first identified in the Sun’s spectrum before being found on Earth.
