Heat Transfer
Heat transfer is the movement of heat from something warm to something cooler, like an oven warming food inside it.
A warm pan sits on a cool countertop. Heat moves from the hot pan down into the counter. The pan slowly cools as the counter warms up. Warm always flows toward cool until both feel the same.
Explaining heat transfer by grade level
When you bake a custard, the oven is hot and the egg mix is cold. Heat moves from the hot oven air into the cold mix. The egg mix gets warmer and warmer. That moving heat is what cooks the custard and makes it firm.
Projects that explore heat transfer
Baking surrounds a potato with hot oven air, so heat moves steadily inward from the surface. Steaming works the same way — hot vapor touches the cooler food and transfers energy into it. In this experiment, you cook potatoes and carrots using several methods and then compare weight, taste, and texture to see how the rate of heat transfer changes the result.
When something warm sits next to something cooler, heat moves between them. In this experiment, a burning nut heats water in a test tube. You measure the rise in water temperature to calculate how much energy the nut released per gram.