Bitesize has changed! We're updating subjects as fast as we can. Visit our new site to find Bitesize guides and clips - and tell us what you think!


Electrostatics - sparks

Positive and negative charges

Objects can be positively charged, negatively charged or neutral (no charge).

A substance that gains electrons becomes negatively charged, while a substance that loses electrons becomes positively charged.

When a charged object comes near to another object they will either attract or repel each other.

  • If the charges are the same - they repel

  • If the charges are opposite - they attract

  • If one is charged and the other is not - they attract

Like charges repel. Unlike charges attract.

Try clicking the text on the right of this diagram to see how the charges behave.

Higher tier only

An atom is made up of two parts - a positively charged nucleus surrounded by negatively charged electrons. In an uncharged (neutral) atom there are the same number of positive and negative charges.

Positively charged necleus surrounded by negatively charged electrons

An atom

When an acetate rod is rubbed with a duster, electrons are transferred from the rod onto the duster, making the rod positively charged. Play the animation below to see how this happens.

Back to Radiation for life index

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.