Scientific Method Chemistry

What is a hypothesis?

• hypothesis is the right answer to an experiment.

• hypothesis is the wrong answer to an experiment.

• hypothesis is an educated guess.

Which step? "I was right!: Touching the cheese makes the cheese moldy."

• make a hypothesis

• draw a conclusion

• experiment

Tags

NGSS.MS-LS1-5

The information you collect while doing your experiment is called

• conclusions

• data

• hypotheses

• procedures

Tags

NGSS.MS-PS1-2

Jessica notices that sugar seems to dissolve faster in hot water than in cold water. She wonders if temperature affects the rate at which sugar dissolves. What is the best hypothesis Jessica could use to test this idea?

• If the water is hot, sugar will dissolve faster.

• Hot water is better for dissolving substances.

• Sugar dissolves because it is sweet.

• Cold water slows down the dissolving process.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Max wants to investigate how the concentration of a solution affects the rate of a chemical reaction. He plans to mix different concentrations of hydrochloric acid with the same amount of magnesium and measure the time it takes for the reaction to complete. What is the independent variable in Max's experiment?

• The concentration of hydrochloric acid

• The amount of magnesium used

• The time it takes for the reaction to complete

• The temperature of the solution

Tags

NGSS.HS-PS1-5

Olivia is testing how different catalysts affect the decomposition of hydrogen peroxide. She uses the same concentration of hydrogen peroxide for each trial but changes the type of catalyst. To ensure reliable results, what should Olivia keep constant in her experiment?

• The type of hydrogen peroxide used

• The temperature of the environment

• The amount of hydrogen peroxide used

• The type of catalyst used

Tags

NGSS.MS-PS1-5

Daniel performed an experiment to see if the surface area of a solid affects the rate at which it dissolves in a liquid. He found that powdered solids dissolve faster than large chunks of the same substance. What conclusion can Daniel draw from this experiment?

• Surface area has no effect on dissolving rates.

• Smaller particles dissolve faster than larger ones due to increased surface area.

• The type of solid determines how fast it dissolves.

• Temperature is the only factor that affects dissolving rates.

Samantha is investigating how the pH level of a solution affects the rate of a reaction. She adds vinegar (an acid) and baking soda to water and observes the reaction speed. How should Samantha measure the pH level's effect on the reaction?

• Measure the temperature of the water before and after the reaction.

• Change the amount of water in each test and observe the reaction.

• Record the time it takes for the reaction to complete at different pH levels.

• Use the same pH level for all tests to ensure consistency.

Tags

NGSS.MS-PS1-2

What is the first step in the scientific method?

• Formulating a hypothesis

• Conducting an experiment

• Making an observation

• Analyzing data

Tags

NGSS.MS-PS2-2

In a chemistry experiment, what is the purpose of a control group?

• To provide a standard for comparison

• To increase the sample size

• To ensure the experiment is valid

• To test multiple variables at once