Teach-Primary-Issue-19.2

Explore the effects of thermal energy by making delicious s’mores in a pizza box oven LAURA MI NTER AND T I A WI LL I AMS www.teachwire.net | 33 To begin, measure and mark out a one-inch (2.5cm) border on the lid of your pizza box. Score along three sides of the border, leaving the side closest to the hinge of the lid intact. Bend the cardboard back to create a large, door-like flap. Line the inside of the box with foil and glue in place. The reflectiveness of the foil will help heat up the inside of the oven when the sun is shining on it. To make the s’mores, break the chocolate into chunks and cut the marshmallows into small pieces. Make a biscuit sandwich with marshmallows and chocolate layered inside. You could assemble your treats in the classroom, or even outside, camping-style. Can children predict what will happen to the soft marshmallows and chocolate when heat is applied? What do they know about states of matter that they can apply to this situation? Check your s’mores every 10 minutes until the chocolate and marshmallows begin to melt. The science behind this is all to do with thermal energy (otherwise known as heat energy). This energy is produced when there is a rise in temperature that causes atoms and molecules to move faster. The foil reflects thermal energy the same way it reflects light, which heats up the air inside the box, melting the chocolate and marshmallows in the s’mores. Place the s’mores into the solar oven and close the lid, propping the flap open with two pieces of dowel or sticks. The foil on the underside of the flap should now be hovering over the plastic-wrapped hole in the lid of the pizza box, with the s’mores underneath. Take your oven into the sunshine. Position the oven so the foil-covered lid is facing the sun; the light needs to reflect off the foil and into the box. Line the bottom of the pizza box with black paper, placing it over the foil; you don’t need to glue it down. This will help the oven retain heat. Cut a piece of plastic wrap, larger than the square cutout of the lid. Stretch it so there are no creases and tape down along all the sides inside the lid. This will also help trap the heat from the sun in the oven. S cience is like a superpower. Everything we know about the world, and our existence in it, is all thanks to scientists. And exploring outside adds to the fun. That's why we decided to get hands-on with this pizza oven project, upcycling elements from the recycling box to create sumptuous s’mores, and investigating the scientific principle of changes in states of matter at the same time. You will need: Pizza box Plastic wrap Scissors Biscuits Foil Chocolate Glue Sticks Marshmallows Laura and Tia are crafters, mothers, and writers. Their book, Outdoor Science (£12.99, Button Books), is out now. F EATURE S S C I ENC E @littlebuttondiaries