7th Grade Science Fall Semester Exam

Front

What is average speed?

Back

Average speed is the total distance traveled divided by the total time taken.

Front

What is the difference between distance and displacement?

Back

Distance is a scalar quantity that refers to how much ground an object has covered, while displacement is a vector quantity that refers to the object's overall change in position.

Front

What does it mean if a quantity is scalar?

Back

A scalar quantity has only magnitude and no direction, such as distance.

Front

What does it mean if a quantity is vector?

Back

A vector quantity has both magnitude and direction, such as displacement.

Front

How do you calculate average speed?

Back

Average speed = Total distance / Total time.

Front

What is a precipitate in a chemical reaction?

Back

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What does a coefficient in a chemical equation represent?

Back

A coefficient indicates the number of molecules or moles of a substance involved in a reaction.

Front

What is the significance of the law of conservation of mass in chemical reactions?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Front

What is the formula for calculating speed?

Back

Speed = Distance / Time.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.