14. A student sets up an experiment with two plants that are each exactly five inches tall. One is given fertilizer and the other is not. After 4 weeks their height is measured again. What is wrong with this experiment?

• Plants naturally grow at different rates. More trials need to be done.
• Plants grow slowly. The time frame is too short.
• There is no control for this experiment.
• The plants need to be taller to get accurate measurements.

16. Four students were working on an experiment with baking soda. Over three trials, the students were required to take the mass of the baking soda. What is the average amount of baking soda used during trial 3?

• 0.4475 g
• 0.440 g
• 1.79 g
• 0.460 g

13. A car tire company is testing a new tire that has proposed improved performance in wet conditions. An experiment was performed on a closed, half-mile track in wet conditions with the same car and driver. Two trials were performed with standard and new Wet Condition tires. What would the tire company MOST LIKELY infer based on this data?

• The hypothesis was neither verified or refuted.
• There is no hypothesis provided.
• The hypothesis of the company is refuted.
• The hypothesis of the company is verified.

12. Susie places 3 beakers in the freezer. The first beaker contains water only, the second contains water and salt, and the third contains a water and sugar solution. Susie recorded the temperature and the time at which each mixture froze. Which is the most appropriate hypothesis for her experiment?

• Salt affects the freezing point of water.
• The addition of salt raises the freezing point of water.
• The addition of sugar lowers the freezing point of water.
• The addition of different substances affect the freezing point of water.

8. What is the dependent variable in the experiment shown?

• number of plants
• amount of fertilizer
• death rate
• mass of plant

Which of the following is NOT a goal of science?

• to investigate and understand the natural world
• to explain events in the natural world
• to establish a collection of unchanging truths
• to use derived explanations to make useful predictions

If you do not understand a direction or part of a lab procedure, you should

• A. figure it out as you do the lab.
• B. try several methods until something works.
• C. ask the instructor before proceeding.
• D. skip it and go on to the next part.

The work of scientists usually begins with...

• testing a hypothesis.
• careful observations.
• creating experiments.
• drawing conclusions.

Information gathered from observing a plant grow 3 cm over a two-week period is called...

• inferences.
• variables.
• hypotheses.
• data.

A scientific hypothesis...

• can be based on personal beliefs or opinions.
• can be tested by experiments or observations.
• does not have to be tested to be accepted as correct.
• is a proven fact with much evidence to support it.