Everything around us is made of tiny particles called atoms. Atoms are the basic units of matter. Elements are pure substances made up of only one type of atom. For example, gold is an element made only of gold atoms.
▸ Atom — The smallest unit of an element that retains the chemical properties of that element.
Example: A single particle of hydrogen.
▸ Element — A pure substance consisting only of atoms that all have the same number of protons in their atomic nuclei.
Example: Oxygen (O), Iron (Fe), Carbon (C).
When two or more different elements combine chemically, they form a compound. For instance, water (H₂O) is a compound made of hydrogen and oxygen atoms.
▸ Compound — A substance formed when two or more chemical elements are chemically bonded together.
Example: Water (H₂O), Salt (NaCl).
Audio narration — reads aloud, works offline
In your own words, summarise the main idea of this lesson.