Some excellent websites:
General:
http://www.scootle.edu.au/ec/viewing/L753/index.html
https://www.scootle.edu.au/ec/resolve/view/L13
Veritasium - a Science video blog
Worth looking at when you want to answer a question.
Year 1 Magic School Bus Games
KS3 Bitesize Science
Some excellent information and games to play
Year 1 Websites
Biology:
Buzz - classification game for year 3
Physical Sciences
Year 4 and 5 Friction
Forces in Action
http://www.bbc.co.uk/schools/scienceclips/ages/10_11/forces_action.shtml
Light and shadows
From KS2 bitesize
Earth and Space Sciences
Comparing planet sizes
Big Bang and the Birth of the Earth
http://www.bbc.co.uk/schools/scienceclips/ages/7_8/rocks_soils.shtml
BBC Science Clips - Earth, Sun and Moon
An animation of how the Earth and Moon move around the Sun.
NASA Kids' Club
Games for children (K - 4).
The Solar System
Water Cycle Quiz
A Scale model of our Solar System
You can add local coordinates and map out where the planets of the solar system will orbit
Mars Science Laboratory
See the latest from the Mars Landing
Solar System facts
Scale of the Universe 2
A look and comparison of the size of everything in the universe
http://www.beaconlearningcenter.com/weblessons/breakingnews/news001.htm
Earth and Sun activity and reading
Chemical Sciences
Decomposing
Sid the Science Kid
Year 1 Website grouping materials
Year 6
http://ecm.det.wa.edu.au/connect/resolver/view/L5826/latest/index.html
http://www.skwirk.com.au/esa/Volcanoes.html
http://volcano.si.edu/reports_weekly.cfm
https://australianmuseum.net.au/uploads/documents/4645/volcano_structure.pdf