Atomic Structure
Atomic Structure
Atoms
- Atoms are the fundamental building blocks of all matter.
- An atom consists of a nucleus, surrounded by electrons.
- All atoms of the same element have the same number of protons in the nucleus.
Nucleus
- The nucleus is located at the centre of the atom.
- It is composed of protons and neutrons, collectively referred to as nucleons.
- Protons have a positive charge, while neutrons carry no charge.
- The nucleus is extremely dense and contains most of the atom's mass.
Electrons
- Electrons are tiny, negatively charged particles that orbit the nucleus.
- Their paths are organised into energy levels or shells, each of which can hold a specific number of electrons.
- The number of electrons in an atom usually equals the number of protons, which makes the atom overall electrically neutral.
Atomic Number
- The atomic number, or proton number, is the number of protons in the nucleus of an atom.
- This number determines which element the atom is.
Atomic Mass
- Atomic mass, or nucleon number, is the total number of protons and neutrons in an atom's nucleus.
- It's measured relative to the mass of the carbon-12 isotope, which has 6 protons and 6 neutrons.
Isotopes
- Isotopes are atoms of the same element (so they have the same number of protons) but with different numbers of neutrons.
- Although isotopes of an element behave the same chemically, they can have significantly different physical properties.
Radioactivity
- Radiation is released by atoms when the balance of energy within the atom is disturbed, often due to changes in the nucleus structure.
- This process is called radioactive decay.
- The three types of nuclear radiation are Alpha (α), Beta (β) and Gamma (γ).