As the kernel is heated, the liquid water evaporates-changes to gas. The gas expands and pushes so hard that it breaks and the starch is blown outward. That is why you hear the popping noise when popcorn is popping. Cooperative grouping and evaluation based on their ability to come up with good explanations and filling out an observation sheet. The sheet can be set up similar to the way it is written up leaving the spaces blank.
Heat is energy that is transferred between two things because of a temperature difference.
Heat flows on its own from a hotter to a cooler substance, regardless of the amount of each substance. Heat is commonly measured in calories, although the joule is preferred. Specific heat is a measure of how much heat is required to raise the temperature of a unit of mass of a substance by one degree. Water has a much higher specific heat than almost anything else. The high specific heat of water is responsible for the differences in climates between the East and West Coasts.