What Is an Exothermic Reaction? — Reading Comprehension

Premium Resource

Grades

Standards

MS-PS3-4
4-PS3-3
4-PS3-2

About This Reader

This science passage introduces students to the idea of exothermic reactions—chemical changes that release heat or light. Aligned with NGSS MS-PS3-4, it explains how energy flows out of the system during burning, explosions, or reactions like those in hand warmers. With familiar examples like campfires and fireworks, the passage helps readers understand how exothermic reactions warm their surroundings and power useful tools. It also compares exothermic and endothermic processes to reinforce student understanding of energy transfer. This resource supports science literacy and reading comprehension skills while connecting classroom content to everyday life and engineering applications.

CONTENT PREVIEW

Have you ever sat near a campfire and felt its heat? That’s an example of an exothermic reaction in action.

An exothermic reaction is a chemical reaction that releases energy, usually in the form of heat or light. These reactions cause the surroundings to warm up because energy is given off as the reaction happens.

A great example of an exothermic reaction is burning wood. When wood burns, it combines with oxygen in the air and gives off heat and light. This reaction is not only warm to the touch, but also bright, like in a fire.

Another example is fireworks. When they explode in the sky, they release energy all at once, producing heat, light, sound, and color. That’s a very fast and exciting exothermic reaction!

Exothermic reactions happen in many places, not just in fires. Hand warmers often use chemical reactions that release heat to keep your hands warm in cold weather. Even when some substances are mixed together in a lab, the beaker may feel warm because of the energy released.

Exothermic reactions are the opposite of endothermic reactions, which absorb energy and make the surroundings cooler.

Understanding exothermic reactions helps scientists, engineers, and even cooks. It explains why fuels burn, how engines work, and why some materials heat up when mixed.

So, the next time you feel warmth from a reaction, you’re likely witnessing an exothermic change!

Fun Fact: Some hand warmers use iron powder and salt. When exposed to air, the iron reacts with oxygen in an exothermic reaction—just like rusting, but faster—and keeps your hands warm for hours!

What is an exothermic reaction?

A reaction that cools down the surroundingsA reaction that absorbs lightA reaction that releases energy as heat or lightA reaction that uses water

What do exothermic reactions do to their surroundings?

Make them colderMake them darkerMake them warmerFreeze them

Which of the following is an example of an exothermic reaction?

Ice meltingPhotosynthesisBurning woodMixing cold water and salt

What do fireworks release during an exothermic reaction?

Ice and snowLight, heat, and soundOxygen onlyWater vapor

What kind of reaction is used in hand warmers?

EndothermicCooling reactionExothermicEvaporation

What is the opposite of an exothermic reaction?

Electric reactionCombustion reactionEndothermic reactionCooling reaction