Subatomic Particles (Protons, Neutrons, Electrons) - SS1 Physics Lesson Note
Subatomic particles are the building blocks of atoms. There are three main types of subatomic particles: protons, neutrons, and electrons. Let's explore each of these particles in more detail:
1. Protons:
- Protons have a positive electrical charge of +1.
- They are located in the nucleus of an atom.
- The number of protons in an atom determines its atomic number and defines the identity of the element.
- Protons have a mass of approximately 1 atomic mass unit (amu).
2. Neutrons:
- Neutrons have no electrical charge (neutral).
- They are also located in the nucleus of an atom, alongside protons.
- Neutrons contribute to the mass of the atom without significantly affecting its chemical properties.
- Neutrons have a mass of approximately 1 amu, which is slightly larger than the mass of protons.
3. Electrons:
- Electrons have a negative electrical charge of -1.
- They orbit the nucleus in specific energy levels or shells.
- Electrons are much smaller and lighter than protons and neutrons.
- They are responsible for the chemical behaviour and reactivity of an atom.
- Electrons have a negligible mass compared to protons and neutrons.
The distribution of protons, neutrons, and electrons determines the overall charge and stability of an atom. The number of protons in the nucleus determines the atomic number and the identity of the element. The total number of protons and neutrons gives the mass number of an atom. The arrangement of electrons in energy levels or shells determines the electron configuration and influences the chemical properties and bonding behaviour of an atom.
It is important to note that subatomic particles can also exist outside of atoms, such as in particle accelerators or in the form of cosmic rays. Additionally, there are other subatomic particles, such as quarks and leptons, that make up protons, neutrons, and electrons at a deeper level, but their discussion goes beyond the scope of this overview.