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What this unit covers

• Formulae: Identify the chemical formulas for the elements and compounds listed in the syllabus.
• Formulae: Explain that the molecular formula of a compound indicates the quantity and types of different atoms in a single molecule.
• Relative masses of atoms and molecules: Explain relative atomic mass, A, as the average mass of an element's isotopes in relation to 1/12th of the mass of a carbon-12 atom.
• Relative masses of atoms and molecules: State that relative molecular mass, M, is calculated by adding together the relative atomic masses. For ionic compounds, the term relative formula mass, M, will be used instead.
• The mole and the Avogadro constant: Identify that concentration can be expressed in grams per cubic decimeter (g/dm³) or moles per cubic decimeter (mol/dm³).
• The mole and the Avogadro constant: Recognize that the mole (mol) is the unit for measuring the amount of substance, and that one mole contains approximately 6.02 x 10²³ particles, known as the Avogadro constant, which can refer to atoms, ions, or molecules.