All matter is fundamentally made up of atoms. Atoms themselves consist of a nucleus containing protons and neutrons, surrounded by electrons. Protons and neutrons are made of even smaller particles called quarks, while electrons belong to a group of elementary particles called leptons. Both quarks and leptons are considered elementary particles, meaning they are not made of anything smaller
. Atoms combine to form molecules, and different atoms correspond to different chemical elements-there are over 100 types of atoms listed in the periodic table. Elements can combine chemically to form compounds, which may have very different properties from their constituent atoms (for example, sodium and chlorine form common salt)
. In summary:
- Matter is made of atoms.
- Atoms are made of protons, neutrons, and electrons.
- Protons and neutrons are made of quarks.
- Electrons are leptons.
- Atoms combine to form molecules, elements, and compounds.
This atomic and subatomic structure is the basis of all physical substances in the universe
