Question

18-8: What is an absorption spectrum?

Short answer

The absorption spectrum of a chemical is the part of the incident radiation that the substance hasabsorbedin a certain frequency range. The absorption spectrum is primarily determined by theatomic and molecularcomposition of the chemical. It is a graph of absorbance versus wavelength.

Step-by-step solution

Principle of the Absorption spectrum

Atomic Absorption spectroscopy (AAS) is based upon the principle that free atoms in the ground state can absorb light of a certain wavelength. Absorption for each element is specific, no other elements absorb this wavelength

Example of Absorption spectrum

The pattern of absorption lines in a spectrum is diagnostic of the types of atoms and molecules present, for example, in the surface layers of a star or the atmosphere of a planet. Absorption lines are seen in the spectra of the Sun and other stars.

 Step 3: Uses of absorption spectrum

Agriculture– analyzing soil and plants for minerals necessary for growth

Environmental Study– determination of heavy metals in water, soil, and air

Food Industry– quality assurance and testing for contamination

Forensic’s – substance identification

Mining– testing the concentration of valuable substances in potential mining areas

Nuclear Energy– monitoring potentially hazardous elements in water and waste output

Petrochemical– analyzing products for metals and other substances that can have adverse affects such as oil and gas

Pharmaceutical– many applications from quality control to detecting impurities in drugs