(1) Endothermic and Exothermic Reactions

Which of the following best describes an exothermic reaction?

• A reaction that absorbs energy from its surroundings.

• A reaction that releases stored energy.

• A reaction that requires sunlight to occur.

• A reaction that decreases the temperature of its surroundings.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

What is the main difference between exothermic and endothermic reactions in terms of energy?

• Exothermic reactions absorb energy, while endothermic reactions release energy.

• Exothermic reactions release energy, while endothermic reactions absorb energy.

• Both exothermic and endothermic reactions release energy.

• Both exothermic and endothermic reactions absorb energy.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

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

• Burning wood.

• Photosynthesis in plants.

• Combustion of gasoline.

• Melting of ice.

Tags

NGSS.HS-PS3-4

Why does a fire feel hot to the touch?

• Because it absorbs energy from your hand.

• Because it releases stored energy as heat.

• Because it stores energy from the surroundings.

• Because it decreases the temperature of the air.

Tags

NGSS.HS-PS3-4

Explain why photosynthesis is considered an endothermic reaction.

• It releases energy in the form of heat.

• It absorbs energy from the sun to convert carbon dioxide and water into glucose and oxygen.

• It decreases the temperature of the plant.

• It releases energy stored in glucose.

Tags

NGSS.HS-LS1-5

A student claims that a reaction is endothermic because the temperature of the surroundings decreased. How would you evaluate this claim?

• The claim is incorrect because endothermic reactions release energy.

• The claim is correct because endothermic reactions absorb energy, causing the surroundings to cool.

• The claim is incorrect because temperature changes do not indicate reaction type.

• The claim is correct because endothermic reactions always produce heat.

Tags

NGSS.HS-PS1-4

• Endothermic, because it absorbs energy.

• Exothermic, because it releases energy.

• Endothermic, because it requires sunlight.

• Exothermic, because it absorbs energy.

Tags

NGSS.HS-PS1-4

If a chemical reaction results in the products having more stored energy than the reactants, what can be inferred about the reaction?

• It is an exothermic reaction.

• It is an endothermic reaction.

• It is a combustion reaction.

• It is a neutral reaction.

Tags

NGSS.HS-PS1-4