Final answer:
Atomic emission spectra are patterns of light emission caused by electrons transitioning between energy levels in an atom, where absorption of a photon leads to higher energy states and emission occurs as they return to the ground state. These spectra are unique to each element and help in identifying the composition of substances.
Step-by-step explanation:
The behavior of electrons within an atom and how they interact with light can be understood through the concept of atomic emission spectra. When an electron absorbs a photon, it moves up to a higher energy level, resulting in an excited state. Conversely, when an electron returns to a lower energy level, it emits a photon. These transitions give rise to specific wavelengths of light that are characteristic of the element in question, producing a spectrum with unique lines, each representing a specific electron transition. In Bohr's model, these energy levels correspond to the concept of quantized orbits, with the innermost orbit representing the ground state. The energy levels are not evenly spaced; as they get further from the nucleus, the spacing between levels decreases. This explains why spectral lines at higher energy transitions are closer together.
Varying elements and ions have unique spectral lines, which allows for the identification of substances through their emitted or absorbed light. The atomic emission spectrum is essential in fields like astronomy, where it helps determine the composition of stars and other celestial bodies. Additionally, atomic emission spectra also explain why fireworks display different colors, as various elements are excited and then emit light at specific wavelengths when they return to their ground state.