Ovenless Awesomeness Rocky Road Recipie

Rocky Road
Ingredients
100g Dark chocolate
1 1/2 Tbsp Golden syrup
70g Butter
50g Marshmallows chopped up
100g Biscuits
Raisins and or cranberries
Method
1) Place biscuits into a bag and crush them until they're broken up. Put aside.
2) Melt the butter, chocolate and golden syrup in the microwave on a gentle heat.
3) Cut up marshmallows into tiny bits and add raisins and or cranberries and your biscuit mix.
4) Mix your butter/chocolate mix together
5) Make into a log on baking paper. Cover in coconut
6) Put your names on the outside and refrigerate in student centre.

Lime Battery

We wanted to see how a battery worked. We put a zinc nail and a piece of copper into a lime and connected it to a voltmeter.
One lime = 0.95 volts
two limes = 1.96 volts
3 limes = 2.9 volts and it lit up an led


Does it depend on the size of the lime?
What if I put more nails and copper in?
Can I use different metals?