Sub-atomic Particles

• Sub-atomic particles are the particles which make up an atom: protons, neutrons, and electrons.
• Protons are positively charged particles found in the nucleus of an atom. They have a relative atomic mass of 1.
• Neutrons are neutrally charged particles that are also found in the nucleus. They also have a relative atomic mass of 1.
• Electrons are negatively charged particles present in the energy levels, also known as shells, orbiting the nucleus. They have negligible mass, effectively zero compared to protons or neutrons.
• The nucleus is the central part of an atom, containing protons and neutrons. It is dense and positively charged.
• The atomic number of an atom quantifies the number of protons in an atom. It helps define the identity of an element.
• The mass number is the sum of protons and neutrons in an atom.
• Isotopes are atoms of the same element that have different numbers of neutrons. They have identical atomic numbers but different mass numbers.
• Ions are atoms or molecules that do not have a neutral charge. They have either gained or lost electrons leading to a positive or negative charge.
• Understand the determination of relative atomic mass and relative isotopic mass based on the C-12 scale.
• The concept of ionisation energy, the energy required to remove an electron from an atom, is also important in the context of sub-atomic particles.
• Apply knowledge of the arrangement of sub-atomic particles, atomic structure, isotopes, and ions to solve questions based on these concepts.