Atomic (adjective)

1. Relating to the atom, the smallest unit of matter that has the chemical properties of an element.
2. Relating to the energy or power released by atomic nuclei, especially in nuclear reactions.

Origin:

Early 19th century: from french atomique or modern latin atomicus, from greek atomos "indivisible".

Examples:

1. The atomic structure of an element is determined by the number of protons and neutrons in its nucleus.
2. The atomic bomb was developed during World War II.
3. The atomic clock is the most accurate timepiece ever made.
4. The atomic energy is harnessed to generate electricity.
5. The atomic theory is the foundation of modern chemistry.