Explain that matter is composed of tiny particles called atoms.

To explain that matter is composed of tiny particles called atoms, start with Universal chemistry ideas and keep the answer inside Key ideas in chemistry. Approved keywords include atom and matter. atom is useful here because in Universal chemistry ideas, atom means the smallest unit of matter that retains the properties of an element. This matters in Key ideas in chemistry because it supports the learning objective to explain that matter is composed of tiny particles called atoms. Use atom only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions. Avoid students often think that matter can be made of larger particles or is continuous rather than discrete; instead emphasize that all matter is made up of tiny, indivisible particles called atoms, which are the fundamental building blocks. Draw a simple diagram of a molecule (e.g., H₂O) and label each atom, then write a short sentence explaining that each atom is a tiny particle that makes up the whole molecule. Seeing atoms as individual units helps students remember that all matter is made of these particles, reinforcing the core concept of matter composition.