PBS.org has a wealth of educational resources that educators can use (and all free!).  For science activities, PBS Kids has three excellent shows: SciGirls, DragonflyTV, and Zoom.  Each show has videos (on Youtube), suggestions for teachers to run the activities in their classrooms, and suit primary school ages.  Ideally, have a specific science topic you are teaching about, and do a search to see if any of the three shows has resources on it.

SciGirls show:

More info – http://www.pbs.org/parents/scigirls

Sample Gravity/Friction Classroom activity – http://www.pbs.org/parents/scigirls/activities/parachute-parade/

DragonFly TV:

Show info – http://www.pbs.org/parents/tvprograms/program-dragonflytv.html

Kid’s website – http://pbskids.org/dragonflytv/

Zoom:

Zoom info – http://www.pbs.org/parents/zoom

Activities – http://pbskids.org/zoom/activities/index.html