Pure substances and mixtures interactive worksheet - Free Printable

Let's solve each part of this worksheet step by step and explain the reasoning behind each answer.

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1. Complete the sentences with these words:

Words to use:
MIXTURES – SINGLE SUBSTANCE – DIFFERENT MATERIALS – HETEROGENEOUS – ROCKS – PURE SUBSTANCE – AIR – SALT WATER – HOMOGENEOUS

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Sentence:
*Gold is a _______________ because it is made up of a _______________. Most things around us are _______________, because they are made up of _______________. _______________ is a mixture of gases, _______________ is a mixture of water, salt and minerals and many _______________ are mixtures of different minerals. We can find two types of mixtures: _______________ mixtures and _______________ mixtures.*

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Step-by-step completion:

- Gold is a pure substance because it is made up of a single substance (pure elemental gold).
- Most things around us are mixtures, because they are made up of different materials.
- Air is a mixture of gases.
- Salt water is a mixture of water, salt, and minerals.
- Rocks are mixtures of different minerals.
- The two types of mixtures are homogeneous and heterogeneous.

✔ Completed sentence:

> Gold is a pure substance because it is made up of a single substance. Most things around us are mixtures, because they are made up of different materials. Air is a mixture of gases, salt water is a mixture of water, salt and minerals and many rocks are mixtures of different minerals. We can find two types of mixtures: homogeneous mixtures and heterogeneous mixtures.

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2. Write HOMOGENEOUS or HETEROGENEOUS:

We need to classify each image based on whether the mixture appears uniform (homogeneous) or non-uniform (heterogeneous).

1. Fruit salad (first image):
- Different fruits visible; not uniform.
→ Heterogeneous

2. Mayonnaise (second image):
- Smooth, uniform appearance.
→ Homogeneous

3. Beaker with sand at bottom (third image):
- Layers visible; solid settled at bottom.
→ Heterogeneous

4. Smoothie (fourth image):
- Uniform color and texture; no visible separation.
→ Homogeneous

✔ Answers:
- Fruit salad: Heterogeneous
- Mayonnaise: Homogeneous
- Sand in liquid: Heterogeneous
- Smoothie: Homogeneous

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3. Match the methods of separating mixtures and definitions:

We have three methods and their corresponding definitions.

#### Images:

1. First image (sieve with particles):
- This shows sieving, where particles of different sizes are separated using a mesh.
→ Matches: *"We can separate solids of different sizes."*

2. Second image (sand and water layers):
- This represents evaporation, where water evaporates, leaving salt or solids behind.
→ Matches: *"We can separate solids that are dissolved in a liquid."*

3. Third image (coffee filter with coffee grounds):
- This is filtration, where liquid passes through a filter, and solid is trapped.
→ Matches: *"We can separate solids from liquids."*

✔ Matching:

| Method | Definition |
|---------------|----------|
| SIEVING | We can separate solids of different sizes. |
| EVAPORATION | We can separate solids that are dissolved in a liquid. |
| FILTRATION | We can separate solids from liquids |

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✔ Final Answers:

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#### 1. Fill in the blanks:

> Gold is a pure substance because it is made up of a single substance. Most things around us are mixtures, because they are made up of different materials. Air is a mixture of gases, salt water is a mixture of water, salt and minerals and many rocks are mixtures of different minerals. We can find two types of mixtures: homogeneous mixtures and heterogeneous mixtures.

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#### 2. Homogeneous or Heterogeneous:

1. Fruit salad → Heterogeneous
2. Mayonnaise → Homogeneous
3. Sand in liquid → Heterogeneous
4. Smoothie → Homogeneous

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#### 3. Matching:

- SIEVING → We can separate solids of different sizes.
- EVAPORATION → We can separate solids that are dissolved in a liquid.
- FILTRATION → We can separate solids from liquids.

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This completes the worksheet! Let me know if you'd like a printable version or explanation in simpler terms.