All foods contain chemical energy, but the amount of chemical energy is dependent of the type of food. the larger the compound, the more chemical bonds present and the greater amount of available chemical energy. we can rank molecule size, from smallest to largest, as sugar, starch, fat. we refer to the stored chemical energy in foods as calories. a calorie is the amount of energy required to raise the temperature of 1 gram of water 1 degree celsius. when we refer to the calories in food, we are really talking about kilocalories or 1000 calories. biology students "burned" 2 grams of food to heat water in a calorimeter in order to determine which food items contain the most usable chemical energy. each group picked two food items to burn. one group chose a saltine and a chip. they hypothesized that the chip with produce a greater change in water temperature when burned. here is the data they collected.