Fair testing

Question 1

Sam wants to know whether giving a plant more water makes it grow taller. Which of the following scientific enquiries would best help Sam answer his question?

Accepted Answer

Do an experiment where some plants receive more water and others receive less water

Answer

Observe how the plants grow without changing the amount of water they receive

Answer

Read a book about how water affects plant growth

Answer

Ask classmates which plant they think will grow taller with more water

Question 2

Sam wants to know which material—plastic, wood, or metal—keeps an ice cube from melting the longest when placed on a sunny windowsill. Which of the following scientific enquiries would best help Sam answer his question?

Accepted Answer

Set up a controlled experiment that tests each material under the same conditions and records the time each ice cube melts.

Answer

Read a book about insulation properties of different materials.

Answer

Ask classmates which material they think will keep the ice cube cold the longest.

Answer

Observe ice cubes melting on the windowsill without changing any materials.

Question 3

Sam notices that some of his lettuce plants are taller than others. Which question should Sam ask to investigate why the height differences occur?

Accepted Answer

Do lettuce plants grow taller when they receive more sunlight than when they receive less sunlight?

Answer

How many lettuce seeds did Sam plant in the garden?

Answer

What color are the lettuce leaves on the taller plants?

Answer

Why do lettuce plants need water to survive?

Try three questions

Sam wants to know whether giving a plant more water makes it grow taller. Which of the following scientific enquiries would best help Sam answer his question?

Sam wants to know which material—plastic, wood, or metal—keeps an ice cube from melting the longest when placed on a sunny windowsill. Which of the following scientific enquiries would best help Sam answer his question?

Sam notices that some of his lettuce plants are taller than others. Which question should Sam ask to investigate why the height differences occur?

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