Loading please wait

The smart way to improve grades

Comprehensive & curriculum aligned

Try an activity or get started for free

Understand the Chemical Formulae of Compounds

In this worksheet, students will explore compounds. The Periodic Table lists all the elements that have been discovered so far, but what is created when these atoms combine?

'Understand the Chemical Formulae of Compounds' worksheet

Key stage:  KS 3

Year:  Year 8 Science worksheets

Curriculum topic:   Chemistry: Atoms, Elements and Compounds

Curriculum subtopic:   Atoms, Elements and Compounds

Popular topics:   Chemistry worksheets

Difficulty level:  

Worksheet Overview

The alphabet contains 26 letters, but how many words can you think of... thousands, hundreds of thousands, millions? Combining the letters of the alphabet allows us to create lots and lots of words.


This is similar to chemistry. The Periodic Table is composed of over a hundred elements and when these elements combine they form compounds. This means that there are billions of possible compounds in existence. 


A compound is made of two or more elements chemically joined together.


Elements can combine during chemical reactions to form new compounds. For example:


Image of magnesium burning



Magnesium + Oxygen Magnesium Oxide


Compounds are usually completely different from the elements that formed them.


Magnesium is a shiny, silver, highly flammable metal.

Oxygen is a colourless gas.

Magnesium oxide, however, is a white powder. 


A molecule is formed when a small group of atoms are joined together.


These atoms may all be the same, such as in hydrogen (H2) which is a molecule of an element, or different, such as water (H2O) which is a molecule of a compound.


Hydrogen molecule Water molecule
Hydrogen Molecule Water Module
Want a bit more help with this before you begin? Why not watch this short video?

What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Get started

Popular Science topics

Try an activity or get started for free