GizmosAnswerKey
Physical ScienceGrade 8-10

Chemical Reactions Answer Key

Investigate the signs of chemical reactions and explore factors that affect reaction rates.

Prior Knowledge Questions

Q1.What is a chemical reaction?

Answer

A chemical reaction is a process where substances (reactants) are transformed into new substances (products) with different properties.

Q2.What are four signs that a chemical reaction has occurred?

Answer

Color change, gas production (bubbles), temperature change, and formation of a precipitate (solid).

Q3.What is the Law of Conservation of Mass?

Answer

Matter cannot be created or destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Activity A – Reaction Rates

Q1.How does temperature affect reaction rate?

Answer

Increasing temperature speeds up reaction rate because particles move faster and collide more frequently with more energy.

Q2.What is a catalyst?

Answer

A catalyst is a substance that speeds up a chemical reaction without being consumed in the process.

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