Atomic Structure
Science

The SI unit of the masses of particles in atoms
Atomic mass unit
The SI unit of the masses of particles in atoms atomic mass unit. An atomic mass unit amu is a small unit of mass used to measure the masses of particles in an atom, like protons and neutrons, where one amu is approximately 112 the mass of a carbon-12 atom.

An 1808 theory by John Dalton. the first theory to relate chemical changes to events at the atomic level
Daltons atomic theory
An 1808 theory by John Dalton, the first theory to relate chemical changes to events at the atomic level, Dalton's atomic theory. Dalton's atomic theory states that matter is made of small, indivisible particles called atoms.

An equation that shows the atomic number and mass number of every particle
Nuclear equation
An equation that shows the atomic number and mass number of every particle. Nuclear equation. A nuclear equation is a representation of a nuclear reaction showing the atomic numbers and mass numbers of the particles involved.

The breakdown of an unstable atomic nucleus, this releases particles and energy
Radioactive decay
The breakdown of an unstable atomic nucleus, this releases particles and energy. Radioactive decay. Radioactive decay is when an unstable atom loses energy and particles over time, turning into a different element.