- Definition: An atom is the smallest unit of a chemical element that retains the properties of that element. It consists of a nucleus made of protons and neutrons, surrounded by electrons in orbit. Atoms are the basic building blocks of all matter in the universe.
- Etymology and Origin: “Atom” comes from the Greek word “atomos,” meaning “indivisible” or “uncuttable.” It is derived from “a-” (not) and “temnein” (to cut). This term was first used by ancient Greek philosophers, like Democritus, to describe the smallest possible piece of matter that could not be divided further. The modern scientific definition of atoms, as divisible units consisting of smaller particles, developed much later.
Atom: Defining the Fundamental Unit of Matter
