Scientific method variables (worksheet) | PDF - Free Printable

Problem Analysis:

The image shows two setups where a plant is being exposed to light. The goal is to identify the change variable (the variable being manipulated in the experiment) and the control variables (variables kept constant to ensure a fair test).

#### Image Description:
- Setup 1: A plant is placed under a light source, and a thermometer is visible.
- Setup 2: Another plant is placed under a different light source, and a thermometer is also visible.
- The key difference between the two setups appears to be the brightness of the light shining on the plants.

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Solution:

#### Question 1: What is the student's change variable?

The change variable is the factor that the student is intentionally altering to observe its effect on the plant. In this case:
- The light sources appear to differ in brightness.
- The angle of the light, type of soil, and air temperature are not visibly altered between the two setups.

Thus, the correct answer is:
c. the brightness of the light is shining on the plant

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#### Question 2: List all the control variables that you can see that the student is keeping constant (the same)

Control variables are factors that are kept constant to ensure that any observed changes in the plant are due only to the change variable. From the image, the following control variables can be identified:
1. Type of plant: Both plants appear to be the same species and size.
2. Type of soil: The pots and soil look identical in both setups.
3. Amount of water: There is no indication that the watering differs between the two plants.
4. Position of the plant relative to the light source: Both plants are positioned similarly under their respective light sources.
5. Air temperature: The thermometers in both setups suggest that the air temperature is being monitored and likely kept constant.
6. Size of the pot: Both plants are in pots of the same size.

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Final Answers:

1. Change variable:
\boxed{c}

2. Control variables:
- Type of plant
- Type of soil
- Amount of water
- Position of the plant relative to the light source
- Air temperature
- Size of the pot

\boxed{\text{Type of plant, Type of soil, Amount of water, Position of the plant relative to the light source, Air temperature, Size of the pot}}