* Ground State: An atom in its ground state has its electrons in the lowest possible energy levels.
* Excitation: When an atom absorbs energy (e.g., from heat, light, or a collision), an electron can jump to a higher energy level, becoming "excited."
* Relaxation: The excited state is unstable. The electron will naturally want to return to its lower energy level. To do this, it releases the absorbed energy as a photon of light (or other forms of electromagnetic radiation).
* Energy Levels and Photons: The energy difference between the excited state and the ground state determines the specific wavelength (and therefore color) of the emitted light.
Think of it like this: Imagine a ball on a staircase. It's most stable at the bottom (ground state). If you give it energy (push it up), it will eventually fall back down (relaxation), releasing energy as it does.
Key Points:
* Excited atoms are unstable: They have excess energy and will quickly return to their ground state.
* Light emission is quantized: The energy of the emitted photon corresponds precisely to the energy difference between the excited and ground states.
* Spectroscopy: This process of absorbing and emitting light is the basis of spectroscopy, which helps scientists study the composition and properties of matter.
