Teaching children science with fire and thermodynamics

As summer grilling season heats up, use the opportunity to teach kids about the science of heat and thermodynamics.

Michigan State University Extension recognizes there are many opportunities for science education that occur in the natural world. This opportunity, around fire and thermodynamics, can be conducted by any group working with children, including families, day-cares, schools or 4-H clubs.

The following activity can be conducted with any type of fire: a campfire, a grill, or something else. WARNING: fire is DANGEROUS. Children should be closely supervised when near fire. Stress safety before conducting any experiments and continue reminding children about safety. Fire and grilling should always be practiced safely around the home or when camping. MSU Extension’s FireWise curriculum has information to protect your life and property from fire. When conducting the experiment, elbow-length welding gloves can go a long way to protecting your hands from the heat.

To begin, start your fire or grill and then ask children the following questions:

  1. What is fire? Ask a child (or an adult) to explain it, and you might find it interesting how difficult it is. If you need assistance, the Alan Alda Center for Communicating Science held a contest in 2013 to see who could best explain this concept to children. The winning result incorporated animation and music to teach the concepts of how fire works.
  2. What burns and what doesn’t? Have children guess and observe from a safe distance while an adult carefully puts something in the fire. Watch what happens and see if their predictions come true. Ask why will a piece of wood burn, but not a rock? Will a paper cup full of water burn? How about chewing gum? A metal pop can? A marshmallow? Why does a phone book burn differently than a single sheet of paper? NOTE: Please do not burn plastics in a fire, they can produce toxic fumes and ash.
  3. What part of the fire is the hottest? Using an infrared or “laser” thermometer, you can check out the temperature at different parts of the fire.
  4. Why is the fire different colors? You can often see oranges, reds, yellows and sometimes blues in different parts of the fire. Some people say blue is hotter, but use your thermometer and check it out.
  5. Does different wood burn differently? Do some kinds of wood burn faster or slower? Hotter or cooler? Does different wood produce different amounts of smoke? Gather pieces of wood the same size from several different trees, put them in the fire and observe what happens. Age and dryness of the wood can also lead to differences in how quickly they will burn. Visit this Utah Extension chart discussing some of the differences. Experiment to see if their chart works with your wood.
  6. Does split wood burn differently than whole logs? Try to find two logs of the same weight: one which is split and another with the bark intact and un-split. See what happens when they burn.
  7. What direction does the smoke go and why? When the wind changes directions and smoke blows into your eyes, it can be annoying and painful. Why does the wind change direction so much? Does the smoke ever go straight up? Why doesn’t smoke go down? How long does it take for the smoke to dissipate? Can you rearrange the wood in the fire to reduce how much smoke is produced?

This easy exercise can help develop your child’s inquisitive nature and a love of science. Enjoy a campfire this summer and enjoy science!

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