Relationship between Atoms, Elements, Molecules, and Compounds
- Atom: The smallest unit of an element, maintaining the chemical properties of the element.
- Element: A substance made up entirely of one type of atom. Examples include hydrogen (H), oxygen (O), and gold (Au).
- Molecule: Two or more atoms bonded together. A molecule can be an element (e.g., O₂) or a compound (e.g., H₂O).
- Compound: A substance made from two or more different elements chemically combined in fixed proportions. For example, water (H₂O) consists of hydrogen and oxygen.
- Key Learning: Students will learn how atoms combine to form molecules, and how molecules of different elements create compounds.
1.2 Assigning Symbols to Elements
- Elements are represented using unique symbols, usually one or two letters. The first letter is always capitalized, and the second, if present, is lowercase. For example:
- Hydrogen (H)
- Carbon (C)
- Sodium (Na)
- Chlorine (Cl)
- Activity: Assign symbols to common elements and practice writing them.
