Define calories and how the body gets energy

A calorie is a unit of energy. In nutrition, calories refer to the energy people get from the food and drink they consume, and the energy they use in physical activity. Calories are listed in the nutritional information on all food packaging. Many weight loss programs center around reducing the intake of calories.

This energy comes from the food we eat. Our bodies digest the food we eat by mixing it with fluids  in the stomach. When the stomach digests food, the carbohydrate  in the food breaks down into another type of sugar, called glucose. Calories are ENERGY that fuel our bodies; much like gasoline fuels our cars.

Explanation:

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

the answer is b & c i believe : )