Key Concepts in Radioactivity and Nuclear Reactions

Radioisotopes

Atoms with unstable nuclei that emit radiation as they decay into more stable forms. .

Radioactive Decay

A spontaneous process where an unstable atomic nucleus loses energy by emitting radiation (alpha, beta, or gamma).

Transmutation

The conversion of one chemical element or isotope into another through nuclear reactions, often as a result of radioactive decay.

Nucleons

The particles found in an atomic nucleus — protons and neutrons.

Strong Nuclear Force

The fundamental force that binds protons and neutrons together in the nucleus, overcoming the repulsive electromagnetic force between protons.

Alpha Decay

A type of radioactive decay where an unstable nucleus emits an alpha particle (^4₂He), decreasing its atomic number by 2 and mass number by 4.

Beta Decay

Radioactive decay where a beta particle (an electron or positron) is emitted. It changes a neutron to a proton (β⁻ decay) or a proton to a neutron (β⁺ decay).

Gamma Emission

The release of gamma rays (high-energy electromagnetic radiation) from a nucleus, usually after alpha or beta decay, without changing the element.

Radioactive Decay Series

A sequence of decays that some radioactive elements go through to reach a stable isotope, with each step producing a different element.

Half-Life

The time it takes for half the atoms in a sample of a radioactive isotope to decay.

Radiochemical Dating

A method of determining the age of materials by measuring the abundance of specific radioactive isotopes and their decay products.

Carbon Dating

A form of radiochemical dating that uses the decay of carbon-14 to determine the age of once-living organisms (effective up to ~50,000 years).

Nuclear Power

The use of controlled nuclear reactions (usually fission) to generate energy, typically for electricity production.

Chain Reaction

A self-sustaining sequence of nuclear fissions, where each reaction releases neutrons that trigger more fissions.

Critical Mass

The minimum amount of fissile material needed to maintain a self-sustaining nuclear chain reaction.

Meltdown

A severe nuclear reactor accident where the fuel rods overheat and melt, potentially breaching containment and releasing radiation.

Regular Operations

The normal, controlled functioning of a nuclear reactor, where energy is generated safely and efficiently without incident.

Cell Damage

Harm caused to biological cells, often by ionizing radiation, which can damage DNA, proteins, or membranes, potentially leading to mutations or cell death.