Answer:
See explanation
Explanation:
Electrons transition between energy levels in an atom due to gain or loss of energy. An electron may gain energy and move from its ground state to one of the accessible excited states. The electron quickly returns to ground state, emitting the energy previously absorbed as a photon of light. The wavelength of light emitted is measured using powerful spectrometers.
Atoms can be excited thermally or by irradiation with light of appropriate frequency.
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
A polyatomic ion.
Examples: Sulfate, Sulfite, Nitrate, Nitrite...
