Worksheet on identifying experimental variables in scientific experiments.

It looks like you've uploaded a worksheet titled "Experimental Variables Worksheet" from a science class, focusing on identifying the independent variable (IV) and dependent variable (DV) in various experiments. Since I can't view images directly, I’ll help you solve each problem based on the text you provided.

Let’s go through each scenario one by one and identify the Independent Variable (IV) and Dependent Variable (DV).

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1. The number of flowers an experimental plant produces is measured every week for two months. The first group grows 200 ml of water each day and no fertilizer. The second group gets 200 ml of water and 1 gram of fertilizer each day. And the third group is given 40 ml of water and 1 gram of fertilizer each day.

- Independent Variable (IV):
The factor that is being changed or manipulated by the experimenter. Here, the amount of water and fertilizer are varied. But since both water and fertilizer are changed, we need to see what's being tested.
→ The amount of water and amount of fertilizer are both manipulated. However, since the experiment compares different combinations, we can say:
IV: Amount of water and amount of fertilizer (or "treatment conditions" — water + fertilizer combination)

But if we’re looking for a single IV, it's likely the type of treatment, which includes both water and fertilizer levels.

So:
✔ IV: Type of treatment (water and fertilizer combination)

- Dependent Variable (DV):
What is being measured? The number of flowers produced.
✔ DV: Number of flowers produced

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2. You give four sunflower plants differing amounts of water (pure water or different concentrations of salt solutions). After a two-week period, the height is measured.

- Independent Variable (IV):
The factor being changed — the amount and type of water (pure water vs. salt solutions).
✔ IV: Type of water (pure water or salt concentration)

- Dependent Variable (DV):
What is measured at the end? The height of the plants.
✔ DV: Height of the sunflower plants

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3. Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is kept outside in normal conditions. Height of the tree is measured each week.

- Independent Variable (IV):
The factor being changed — humidity levels.
✔ IV: Humidity level

- Dependent Variable (DV):
What is being measured? The height of the trees over time.
✔ DV: Height of the trees

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4. Four plant clones are grown under different amounts of water for a three-week period. First plant receives 100 milliliters. The second plant receives 200 milliliters. The third plant receives 100 milliliters. The fourth plant receives only rainwater; the plant only receives natural ways of receiving water. The height of the plants is recorded daily.

- Independent Variable (IV):
The amount and source of water given to the plants.
→ This includes: 100 mL, 200 mL, and rainwater (natural).
✔ IV: Amount and source of water (e.g., controlled watering vs. rainwater)

- Dependent Variable (DV):
What is being measured? The height of the plants.
✔ DV: Height of the plants

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✔ Final Answers:

#### 1.
- IV: Type of treatment (water and fertilizer combination)
- DV: Number of flowers produced

#### 2.
- IV: Type of water (pure water or salt concentration)
- DV: Height of the sunflower plants

#### 3.
- IV: Humidity level
- DV: Height of the trees

#### 4.
- IV: Amount and source of water
- DV: Height of the plants

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🔍 Explanation:

- Independent Variable (IV): The thing you change or manipulate in the experiment.
- Dependent Variable (DV): The outcome you measure — it depends on the IV.

This worksheet helps students understand how to distinguish between variables in scientific experiments. Always ask:
- “What did the scientist change?” → That’s the IV.
- “What did they measure?” → That’s the DV.

Let me know if you'd like this formatted as a completed worksheet!