Energy-level diagram

Definition

An energy-level diagram is a graphical representation showing the allowed energy states (or levels) of an electron in an atom. These diagrams illustrate transitions between different energy levels, often using arrows to indicate the absorption or emission of photons.

5 Must Know Facts For Your Next Test

1. Energy levels are quantized, meaning electrons can only occupy specific energy states.
2. In Bohr's model of the hydrogen atom, electrons orbit the nucleus in discrete energy levels characterized by quantum numbers.
3. The lowest energy level is called the ground state, and higher levels are called excited states.
4. Transitions between energy levels involve the absorption or emission of photons with energies equivalent to the difference between those levels.
5. The formula for the energy difference between two levels in a hydrogen atom is given by $\Delta E = -13.6 \left( \frac{1}{n_f^2} - \frac{1}{n_i^2} \right)$ eV, where $n_f$ and $n_i$ are the final and initial quantum numbers.

Review Questions

• What does an energy-level diagram represent?
• How does Bohr's model explain electron transitions between different energy states?
• What happens when an electron moves from a higher energy level to a lower one?

Related terms

Quantum Number: A number that specifies the properties of electrons in an atom, including their energy levels.

Photon: A particle representing a quantum of light or other electromagnetic radiation, which carries energy proportional to its frequency.

$\Delta E = -13.6 \left( \frac{1}{n_f^2} - \frac{1}{n_i^2} \right)$ eV: The formula used to calculate the difference in energy between two electron orbits in a hydrogen atom.