Energised Reactions: Chemical Changes
Energised Reactions: Chemical Changes
Lesson duration is: 30 minItems in this lesson
Energised Reactions: Chemical Changes
What do you already know about energy in chemical reactions?
Learning Objective
At the end of the lesson you will be able to describe energy changes in chemical reactions and explain the difference between exothermic and endothermic processes.
What Is Energy in Chemistry?
Energy is the ability to do work or produce change. Chemical reactions involve energy being absorbed or released.
Exothermic vs. Endothermic
Release energy to their surroundings, usually as heat. Often feel warm.
Endothermic Reactions
Exothermic Reactions
Absorb energy from their surroundings. Often feel cold.
Examples of Exothermic Reactions
Burning fuel and mixing water with calcium chloride are exothermic; they release heat.
Examples of Endothermic Reactions
Photosynthesis and dissolving ammonium nitrate in water are endothermic; they absorb heat.
Activation Energy
The minimum energy needed to start a reaction is called activation energy. Some reactions need a spark or heat to begin.
Energy Diagrams
Energy diagrams show how energy changes during a reaction. Look for the rise (activation energy) and fall (energy released or absorbed).
Write down 3 things you learned in this lesson.
Write down 2 things you want to know more about.
Ask 1 question about something you haven't quite understood yet.
