When we studied siphons, we found that to make fluid flow you need a pressure difference (or a height difference) from one end of a tube to the other. The pressure supplies the energy that makes it go. Electrical current needs energy to make it flow, too: voltage, the electrical equivalent to pressure.

Main pages in this section	Estimated time required	Link to activities in teacher manual
Exploring batteries	30 minutes	..
Make a battery	30 minutes	-
Capacitor	30 minutes	..
Science content: about batteries and capacitors	30 minutes
Discussion of batteries and capacitors	30 minutes

Why study batteries and capacitors?
Comments on home-made batteries

Materials needed for this section

• batteries *
• battery holders *
• wires with clip ends *
• light bulb and socket *
• buzzer *
• capacitor *
• light emitting diodes *
• 4 brass washers and 4 zinc-plated washers *
• pipette *
• vial of "battery fluid" *
• a small piece of aluminum foil *
• squares of paper towel *
• capacitor *

Next section:Resistance