Atomic and Molecular Spectra refer to the patterns of light emitted or absorbed by atoms and molecules. When energy is added to an atom or molecule, electrons can jump to higher energy levels. When they return to their original levels, they release energy in the form of light, creating a spectrum unique to each element or compound. These spectra can be observed as lines or bands in a spectrum, known as emission or absorption spectra. Scientists use these patterns to identify substances and understand their properties, making spectroscopy a vital tool in fields like chemistry and astronomy.