Basic chemistry help for students and teachers


Interactive Chemistry Worksheets for Students


Periodic table

Naming compounds

Basic formula

Simple compounds

Ionic compounds 1

Ionic compounds 2

Chemical suffixes

Old chemical names

Hydrocarbons - Alkanes

Alkanes, alkenes & alkynes

Alkanols to alkanoic acids


Common compounds

Common formula quiz

Acids, bases and salts

Covalent compounds

Printable worksheets



Assumed perquisite knowledge:

Students understand the difference between a physical change and a chemical change

What is a chemical reaction?

  1. A chemical reaction occurs when substances combine or breakdown to produce something NEW.
  2. A chemical reaction is accompanied by a chemical change. eg. A permanent change in color or the production of a gas.

    Chemical changes indicate that something new has been produced. eg. The permanent color change produced as bread is toasted in a toaster or the smoke from a burning match.

  3. Chemical reactions are generally difficult to reverse. eg. Turning a slice of toast into a slice of fresh bread.

The chemicals that react are called the reactants.

The new materials that are produced are called the products.

A chemical reaction can be shown by the use of a word equation. The means 'give or produce'

Reactants   Products

chemicals that react chemicals that are produced

Examples of chemical reactions

1. Hydrogen + oxygen   water

 H2 + O2 2H2O

2. Hydrogen peroxide water + oxygen

2H2O2  2H2O + O2

3. Magnesium + oxygen magnesium oxide

2Mg + O2 2MgO

4. Sodium chloride sodium + chlorine

 2NaCl 2Na + Cl2