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


Chemical change

A chemical change is a sign that indicates that a chemical reaction has occurred.

Chemical changes include

  • The production of a gas. Eg. Fizz from sherbet
  • A permanent color change. Eg. A red solution changing to a colorless solution
  • The production of light. Eg. Glow in the dark light sticks which is an example of chemiluminesce
  • The production of a flame. Eg. A Bunsen burner
  • The dissolving of an insoluble solid. Eg. Magnesium dissolving in acid.
  • The production of an insoluble solid. Eg. The production of a precipitate

These changes indicate that something new has been produced.

Physical changes on the other hand are easy to reverse and don't produce anything new. They only involve a change in the physical states (solid. liquid and gas). eg. The melting of an ice cube and steam being produced from a kettle.