8th Grade 1st Semester Review

Front

What is a chemical reaction?

Back

A process where substances (reactants) transform into different substances (products), often involving energy changes.

Front

What are the signs of a chemical reaction?

Back

Common signs include the production of light or heat, formation of a gas, and formation of a precipitate.

Front

What is NOT evidence of a chemical reaction?

Back

Melting is not evidence of a chemical reaction; it is a physical change.

Front

What is acceleration?

Back

Acceleration is the rate of change of velocity of an object, indicating how quickly it speeds up or slows down.

Front

How do you determine which rocket has the greatest acceleration?

Back

Compare the change in velocity over time for each rocket; the one with the highest value has the greatest acceleration.

Front

What is the Hertzsprung-Russell Diagram?

Back

A scatter plot of stars showing the relationship between their absolute magnitudes and stellar classifications.

Front

Which stars are hotter than our sun according to the Hertzsprung-Russell Diagram?

Back

Stars that are located to the left of our sun on the diagram are typically hotter.

Front

What galaxy do humans live in?

Back

Humans live in the Milky Way galaxy.

Front

Where is Earth located in the Milky Way galaxy?

Back

Earth is located in the middle of a spiral arm of the Milky Way.

Front

What is photosynthesis?

Back

Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.