More guides on this topic

• Formulae and equations - OCR 21st Century
• How has the Earth's atmosphere changed over time, and why?
• What is the evidence for climate change? - OCR 21st Century
• How can scientists help improve the supply of potable water?

Related links

• Combined Science Exam practice
• Personalise your Bitesize!
• Jobs that use Science
• ´óÏó´«Ã½: Science and Environment