Four experiments towards the Scientist badge that Cubs will love doing. My Cubs would happily have spent a further hour on these (particularly the last two) so you could happily split them over two nights.
Reactions - Pennies: a cut down version of the Rolls Royce experiment
Living world - Grow Something Disgusting: an experiment with a good scientific method to grow mould - it has the Yuk factor that Cubs seem to love! Note: they need to bring the bags back the next week.
Interacting With Energy - Lollipop stick catapults: Catapults and ping pong balls - almost endless fun
Reactions - Exploding Baggies: Speed, tension and a (small) explosion - what's not to like!
All resources are listed on the instruction sheet as well.
You need :
Pennies: White vinegar, salt, jam jars/containers, tablespoon, teaspoon, kitchen roll, water, dirty copper coins
Grow something Disgusting: bread, ziplock bags, water, biro, teaspoon
Lollipop stick catapults: lollipop sticks, elastic bands, milk bottle lids, ping pong balls
Exploding baggies: White vinegar, ziplock bags, kitchen roll, sodium bicarbonate (eBay) tablespoon, water
See download sheet.
We combined these experiments with a pond dipping expedition, an electronics evening and a rocket building and flying session to cover all the badge requirements. There is no such thing as too much science :)
The badge requirements I have set up are a 'best fit'.
I hope your Cubs enjoy it as much as mine did - we all had a ball!