Energy Levels in Atoms: Electron Shells and Spectroscopy

Energy levels

Fixed distances from the nucleus where electrons may be found.

Electrons

Particles that move around the nucleus, which are tiny and negatively charged.

Charge of the nucleus

Positive.

Comparison of energy levels

Compared to the steps of a staircase.

Niels Bohr

Who explained the concept of energy levels.

Reason electrons stay in regions

Each electron has a fixed amount of energy that keeps it moving around the nucleus.

Regions called by Bohr

Energy levels.

Arrangement of energy levels

In layers or shells, similar to an onion.

Atoms emitting light

The light has particular colors that correspond to specific wavelengths.

Emission of specific colors of light

Means definite transformations occur inside the atom when electrons change energy levels.

Observation of light in a spectroscope

Proves that electrons must occupy levels of fixed energy.