Fundamental particles: protons, neutrons, and electrons
Fundamental Particles Overview
- Atoms are made up of three main fundamental particles: protons, neutrons, and electrons.
- The nucleus of an atom contains protons and neutrons, while electrons orbit around the nucleus.
Protons
- Charge: Protons have a +1 charge.
- Mass: Relative mass of a proton is approximately 1 atomic mass unit (amu).
- Protons are found in the atom's nucleus.
- The number of protons in the nucleus determines the atomic number of an element, defining its identity.
Neutrons
- Charge: Neutrons have no charge; they are neutral.
- Mass: Relative mass is similar to that of a proton, approximately 1 atomic mass unit.
- Neutrons are located in the nucleus along with protons.
- The number of neutrons can vary within atoms of the same element, leading to different isotopes.
Electrons
- Charge: Electrons possess a -1 charge.
- Mass: Electrons have a negligible mass compared to protons and neutrons, approximately 1/1836 atomic mass unit.
- Electrons are found in various energy levels or shells surrounding the nucleus.
- The number of electrons generally equals the number of protons in a neutral atom, ensuring overall charge balance.
General Properties
- Atomic Structure: Most of an atom's mass is concentrated in its small, dense nucleus, whereas the electrons occupy most of the atom's volume.
- Forces: The electrostatic force binds electrons to the nucleus, while the strong nuclear force holds protons and neutrons together within the nucleus.
- Isotopes: Atoms of the same element with different numbers of neutrons. They have the same number of protons but differ in mass number.