PBS Kids suggests that making a lemon or potato battery educates and entertains students in Key Stage 2. To begin, take two lemons and roll them around in your hand to loosen the juice inside. Using a knife, carefully cut two 1-inch slits into each lemon. Cut both slits on each lemon on the same side; when you place the lemons on a surface, both of the slits on each lemon should face upwards.
Treat three 12-inch pieces of copper wire as follows: on the first, wrap two inches at the end of the wire around a penny; on the second, wrap two inches at the end of the wire around a paperclip; and on the third, wrap another penny with one end of the wire and a paperclip with the other. For the two wires with only one item attached, insert the item-wrapped side into the slits of each lemon. Attach the paperclip side of the wire with two items wrapped to it into the lemon with the penny in it. Push the penny side in the other lemon. Attach the two open wires to the different terminals in a clock and watch it go.
Science Made Simple came up with an experiment that allows kids to observe and learn about various winter animal rituals. For this experiment, the child spends time observing the winter patterns of various animals (outside with proper winter clothing or through the student's windows at home) and then combines these patterns with animal research to determine what actions the animals take in the winter. Customize the amount of observation time for the project--small projects may require a few hours of observation, while larger projects may require weeks.
To make a more advanced project for Key Stage 2 students, have them write or sketch out the similarities between human behavior and animal behavior in the winter. For example, donning a "winter coat," traveling to warmer climates and creating a warm living environment.
The Science Museum created a science project for Key Stage 2 level students to create three-dimensional shadow puppets. For this project, you need to setup two different colored lights in a dark classroom and give the students 3D glasses with correspondingly colored lenses. When the students create shadow puppets on the wall, the lenses will create the illusion of three-dimensional shadow puppets. This project teaches students how the brain receives information from the eye, as well as the reason we see in "three dimensions," rather than seeing the world as a flat surface.