Chemical formulae
I can use chemical symbols to write down chemical formulae for elements and compounds.
Chemical formulae
I can use chemical symbols to write down chemical formulae for elements and compounds.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- The symbols for each element (each type of atom) a substance contains, appear in its chemical formula.
- Numbers (subscripts) next to chemical symbols in a formula show the numbers of each type of atom in a compound.
- Each compound contains a different combination of elements.
- Some compounds contain the same elements as other compounds, but in a different ratio.
Keywords
Chemical symbol - One or two letters used to represent a chemical element. The first letter is always a capital letter, e.g. Br represents bromine.
Chemical formula - A representation of either the number of atoms or ratio of atoms of each element in a substance, e.g. H₂O is water = 2 x hydrogen + 1 x oxygen
Common misconception
Writing subscript values as superscript values.
Subscript values show the number of the atoms, while superscript in maths is used to square a value and so does not apply to chemical formulae.
To help you plan your year 8 science lesson on: Chemical formulae, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 8 science lesson on: Chemical formulae, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 science lessons from the Atoms, elements and compounds unit, dive into the full secondary science curriculum, or learn more about lesson planning.
Equipment
Licence
Starter quiz
6 Questions
O
O₂
H₂O
H₂
A substance that cannot be broken down into simpler substances.
The smallest unit of a chemical element.
Anything that has mass and takes up space.
A substance composed of only one chemical substance.
Two or more atoms bonded together (usually non-metals).
Two or more different types of atoms bonded together.
Exit quiz
6 Questions
Ne
CO
O₂
N₂ and CO₂