Atomic structure: protons, neutrons, electrons

An atom is made of a nucleus (protons and neutrons) surrounded by electrons, and different elements are made of atoms with different numbers of protons. Those atoms can combine into molecules: water is always two hydrogen atoms and one oxygen atom joined together, and carbon dioxide is always one carbon atom and two oxygen atoms. Not every substance is made of separate molecules, though: table salt and diamond are extended structures, made of the same atoms repeating in a pattern that stretches on indefinitely rather than breaking into small, separate units. Scientists build models to show exactly which atoms make up a molecule or extended structure and how they're arranged.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report