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Knowledge and Skills Statement

Science concepts. The student understands the energy changes that occur in chemical reactions.

The further explanation is designed to be a resource for educators that helps them better understand the topic their students are learning. Further explanations may be written at a more complex level than would be expected for students at the grade level.

Students may make the connection between calorimetry and calories in food.  A calorie is a unit that is used to measure energy. The "Calorie" used on a food package is actually a kilocalorie, or 1,000 calories. A Calorie (kcal) is the amount of energy needed to raise the temperature of 1 kilogram of water 1 degree Celsius. So the Calorie on a food package is 1,000 times larger than the calorie used in chemistry and physics.

The original method used to determine the number of kcals in a given food directly measured the energy it produced when burned. The food was placed in a sealed container surrounded by water—an apparatus known as a bomb calorimeter. The food was completely burned and the resulting rise in water temperature was measured. While this is not used today to determine the energy content of food, it is used in chemistry labs to compare the amount of energy in various substances.

Glossary terms and definitions are consistent across kindergarten through high school in the TEKS Guide. The definitions are intended to give educators a common understanding of the terms regardless of what grade level they teach. Glossary definitions are not intended for use with students.

the field of science that deals with the measurement of the thermal aspects of a body in order to examine its physical and chemical changes

a measurable quantity that describes how much change can occur within a system

Research

Navrotsky, Alexandra. "New Developments in the Calorimetry of High-Temperature Materials." Engineering 5, no. 3 (2019):366-371. https://doi.org/10.1016/j.eng.2019.03.003

Summary: