Energy Level

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