ENERGY CONTENT

Here is the label from our delicious new BALISCIOUS snack bar that shows you what is in it and just how healthy it is. It tells you all about the nutrients in it and how much energy you get when you eat it. It is important to know this so you can control how many calories you are having, whether there is a good balance of nutrients and so you can make you own decision as to if you want to eat it.

How Students Investigate Energy Content

In order to see how much energy there is in a certain food, you can set it on fire and burn it under a test tube of water and see how much hotter the water gets. From this you can calculate how much energy the food has in it.

The pictures above show how this can be done. Befoe you start. Weight the test tube empty. Put some water in it and weigh it again to work out the mass of the water.Measure the temperature of the water in the test tube using the thermomenter, then weigh the food sample to see how much mass it has. Attach it to a needle and set fire to it using a Bunsen Burner. Hold the food under the test tibe of water until the food is all burned away. Measure the temperature of the water again. The energy from the food per gramme = Mass of the water (g) x temperature rise (degrees c) x 4.2 mass of the food (g) In a proper science lab, scientists would probably use a Calorimeter like in the picture below which would give a more accurate result.

Picture from Nuffield Foundation

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