Atomic and Nuclear Physics-Chapter 7(HL)

Discrete energy

Emission spectrum representing different possible wavelengths of light emitted by an atom.

Emission spectrum

Series of bright lines representing the wavelengths that can be emitted by an atom.

Radioactivity

Spontaneous emission of particles and energy from an unstable nucleus.

Nuclear transmutation

Transformation of one element to another through nuclear reactions.

Nuclear fission

Splitting of a heavy nucleus into lighter nuclei, with the release of energy.

Critical mass

Minimum mass of fissile material needed to maintain a chain reaction.

Nuclear fusion

Joining of light nuclei to form a heavier nucleus, releasing energy.

Isotopes

Atoms with the same number of protons but different numbers of neutrons.

Radioactive decay

Unstable nuclei emit particles and energy spontaneously.

Half-life

The time required for half the quantity of a radioactive substance to undergo decay.

Unified atomic mass unit (u)

A standard unit of mass for atoms and molecules.

Mass defect

The difference between the mass of separated nucleons and the mass of the nucleus.

Binding energy

The energy required to disassemble a nucleus into its protons and neutrons.