The three main subatomic particles that make up an atom are:
- Protons
- Charge: Positive (+1)
- Location: Found in the nucleus (center of the atom)
- Mass: About 1 atomic mass unit (amu)
- Importance: The number of protons determines the atomic number of an element, which defines what element it is (e.g., Hydrogen has 1 proton, Helium has 2).
- Neutrons
- Charge: Neutral (0), no charge
- Location: Found in the nucleus with protons
- Mass: About 1 amu (slightly heavier than a proton)
- Importance: Neutrons add mass and stability to the atom. Different numbers of neutrons form isotopes of the same element.
- Electrons
- Charge: Negative (–1)
- Location: Move in regions called electron shells/orbitals around the nucleus
- Mass: Very small (about 1/1836 the mass of a proton)
- Importance: Electrons are responsible for chemical bonding and electricity, since they can move or be shared between atoms.
Together, these particles make up the structure of the atom: a dense nucleus (protons + neutrons) at the center, surrounded by electrons in space around it.