☯ Concept Cartoons ☯
Table of Contents
1 Chemistry Metals and Ores 13 - How does a cold spoon get hot?
Have you talked about your ideas? Do you agree with any of the characters or do you think something different? Do you all have the same ideas? Here are some ways of finding out more. Find out what kind of kitchen utensils are used for stirring food in a pan and what they are made from. Collect several kitchen spoons made from different materials (e.g. wood, metal, plastic, silicon), put them in hot water and see what happens. Talk about where is the hottest part of the spoon and where is the coldest. What kinds of material would be good for making barbeque tongs, and why? Safety note: the spoons may get very hot.
Here’s what a scientist might say. Did you find any evidence to support or justify these ideas? Are there any questions that you still need to answer? A metal spoon is a solid, made of particles that are packed closely together. They cannot change places or move from one end to the other. When a solid is heated the particles in it vibrate more. The higher the temperature, the more they vibrate. The particles in the spoon that are being heated vibrate more, collide with the particles next to them and make these vibrate more, and these collide with the particles next to them. The energy is transferred through the spoon by particles colliding and passing on energy to the next group of particles. This process is called conduction. The energy is in the movement of the particles, and this is not affected by gravity or the angle of the spoon. Hot gases and liquids rise in a process called convection, but this only happens in liquids and gases where the particles can move around freely. Create an annotated diagram to show how energy is transferred when sausages are being cooked in a pan.