when atoms are rearranged to make new products and changes can be observed e.g. bubbles of gas forming.

occurs in one direction only where the reactants are converted into the products.

elements or compounds before a reaction takes place. Reactants are found on the left hand side of a chemical equation.

elements or compounds that are formed after a reaction has taken place. Products are found on the right hand side of a chemical equation.

Characteristics of chemical reactions

Science

Conservation of mass and balanced symbol equations

Chemical reactions: oxidation

Chemical reactions: combustion

Chemical reactions: decomposition

Chemical reactions: precipitation

In the Acids and Bases unit, pupils will build on their understanding of chemical reactions to learn about the properties of acids, bases, alkalis, and the neutralisation reaction.

In the Atoms, Elements and Compounds unit, pupils learned about atoms, elements, and compounds and how particles reorganise in a chemical reaction.

This unit covers the conservation of mass in changes of state and chemical reactions, including atom rearrangement. It also focuses on representing reactions with formulae and equations, exploring combustion, decomposition, and displacement, and distinguishing chemical from physical changes.

Understanding chemical reactions

Physical activity and equipment requiring safe use

A process where atoms are rearranged to form new substances

Where are products found in a chemical equation?

What do bubbles indicate in a chemical reaction?

Which observation(s) always indicate a chemical reaction has taken place?

{{}} are the elements or compounds before a reaction takes place.

Most chemical reactions can be classed as {{}} reactions, because the reaction occurs in one direction only (where the reactants are converted into the products).

When a substance changes from a solid to a liquid, it is called {{}}.

Which of the following is an example of a chemical change?

A {{}} change is one that does **not** produce new substances and can often be reversed.

Which of the following represents a physical change?

Physical changes produce new substances, chemical changes do not.

Chemical changes produce new substances, physical changes do not.

Physical changes are irreversible, chemical changes are reversible.

Chemical changes involve only a change in state.

What is the main difference between a physical change and a chemical change?

An {{}} is a substance made of one type of atom.

Starter Quiz

When a substance changes from a solid to a liquid, it is called .