Energy Level
Contents
Key Stage 4
Meaning
Energy Levels are another name for the electron shells or orbitals around the nucleus where electrons can exist.
About Energy Levels
- The existence of energy levels in atoms is part of the Bohr model of the atom.
- The electron orbitals in atoms each correspond to electrons with a certain amount of energy, which is why they are also called energy levels.
- Electrons cannot exist anywhere between the energy levels they can only exist in one energy level or another.
- In chemistry electrons are seen as fixed in their energy levels but in physics the electrons can move to a higher energy level by the absorption of energy and can drop down into an empty energy level below by emitting energy.
- The wavelengths of electromagnetic wave depend on the energy difference between the energy levels in atoms.
This diagram shows an electron gaining energy by absorbing an electromagnetic wave and moving to a higher energy level (becoming excited). | This diagram shows an excited electron losing energy by emitting an electromagnetic wave. As it does this the electron falls back down to a lower energy level. |
- If an electron in an the highest energy level, known as the outer shell, gains enough energy it can leave the atom completely so they atom becomes a positive ion.
References
AQA
- Energy level of electrons, pages 13, 18-19, GCSE Chemistry; Third Edition, Oxford University Press, AQA
- Energy levels (atoms), page 197, GCSE Combined Science; The Revision Guide, CGP, AQA
- Energy levels (electron shells), pages 22, 43-45, GCSE Chemistry, CGP, AQA
- Energy levels (electron shells), pages 22, 43-45, GCSE Combined Science Trilogy; Chemistry, CGP, AQA
- Energy levels (shells), page 117-18, GCSE Combined Science Trilogy 1, Hodder, AQA
- Energy levels (shells), pages 2,3,5, GCSE Chemistry, Hodder, AQA
- Energy levels in atoms, page 43, GCSE Physics; The Revision Guide, CGP, AQA
- Energy levels in atoms, pages 111, 201, GCSE Combined Science Trilogy; Physics, CGP, AQA
- Energy levels in atoms, pages 123, 243, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA
- Energy level diagrams, pages 155, 156, 167, GCSE Combined Science Trilogy; Chemistry, CGP, AQA
- Energy level diagrams, pages 180, 181, 199, GCSE Chemistry, CGP, AQA
Edexcel
- Energy levels in atoms, pages 128, 151, 153, 154, GCSE Physics, CGP, Edexcel
- Energy levels, pages 49, 50, GCSE Physics; The Revision Guide, CGP, Edexcel
Key Stage 5
Meaning
Energy levels are the discrete amounts of energy that electrons in an atom can have.
About Energy Levels
- Electrons occupy specific energy levels or shells around the nucleus.
- When an electron absorbs energy, it can move to a higher energy level (excitation in which the atom is said to be excited. NB: not the electron itself).
- When an electron falls to a lower energy level, it emits energy in the form of a photon.
- The energy difference between levels determines the frequency of the emitted or absorbed photon.
- Energy levels are quantized, meaning electrons can only exist in these specific levels and not in between.
- The transitions between energy levels are responsible for the absorption and emission spectra of atoms.