Metals and non-metals worksheet - Free Printable

Let's go through each question step by step and solve them with explanations.

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Question 3

We are given a list of properties:

- Electrical insulator
- Poor thermal conductor
- Good electrical conductor
- Boiling point -153°C
- Good thermal conductor
- Melting point above room temperature
- Magnetic
- Melting point 3422°C

#### a) Magnesium is a metal. Give two properties of magnesium from the list above. (2 marks)

Answer:
1. Good electrical conductor
2. Good thermal conductor

Explanation:
Magnesium is a metal, and metals typically conduct electricity and heat well. The list includes "good electrical conductor" and "good thermal conductor" — both apply to magnesium. It also has a melting point above room temperature (around 650°C), but that’s not in the list directly. However, since we’re limited to the provided list, these two are correct.

> ✔ So, pick:
> 1. Good electrical conductor
> 2. Good thermal conductor

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#### b) Krypton is a gas used inside a light bulb. Give two properties of krypton from the list above which make it a good material to use. (2 marks)

Answer:
1. Electrical insulator
2. Boiling point -153°C

Explanation:
Krypton is a noble gas used in light bulbs because:
- It is an electrical insulator, so it doesn't conduct electricity and won’t short-circuit the filament.
- Its boiling point is -153°C, meaning it remains a gas at room temperature and even at high temperatures inside the bulb (since it boils at such a low temperature, it stays gaseous).
- Also, being inert (not reactive), it prevents oxidation of the filament.

> ✔ From the list, the best two are:
> 1. Electrical insulator
> 2. Boiling point -153°C

(Note: Although “poor thermal conductor” might seem relevant, the key reasons for using krypton are its inertness and insulating properties.)

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#### c) Tungsten is used to make the filament inside a light bulb. Give two properties from the list above which make it a good material to use. (2 marks)

Answer:
1. Melting point 3422°C
2. Good electrical conductor

Explanation:
Tungsten is ideal for filaments because:
- It has an extremely high melting point (3422°C), so it can get very hot without melting.
- It is a good electrical conductor, allowing current to flow through it and produce light.

> ✔ So, choose:
> 1. Melting point 3422°C
> 2. Good electrical conductor

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Question 4

Complete the table based on properties.

| Substance | Melting point °C | Electrical conductivity | Solubility in water | Effect of heating in air | Metal, non-metal or compound |
|----------|------------------|-------------------------|----------------------|----------------------------|-------------------------------|
| A | 113 | Very poor | Insoluble | Burns to form one product – an acidic gas | ? |
| B | 962 | Very good | Insoluble | Loses its shiny surface | ? |
| C | -182 | Very poor | Almost insoluble | Burns to form two new substances | ? |

Let’s analyze each:

#### Substance A
- Melting point = 113°C → relatively low (non-metal like sulfur)
- Very poor electrical conductivity → typical of non-metals
- Insoluble in water
- Burns to form one product – an acidic gas → suggests a non-metal (e.g., sulfur burns to form SO₂, an acidic gas)

✔ Conclusion: Non-metal

#### Substance B
- Melting point = 962°C → high, typical of metals
- Very good electrical conductivity → characteristic of metals
- Insoluble in water
- Loses its shiny surface when heated → this is a sign of oxidation, common in metals (e.g., copper or iron forming oxides)

✔ Conclusion: Metal

#### Substance C
- Melting point = -182°C → very low → likely a gas at room temp
- Very poor electrical conductivity → non-metal
- Almost insoluble
- Burns to form two new substances → could be a compound? But let’s think.

Wait: If it burns to form two new substances, that implies a chemical reaction producing multiple products — possibly a compound decomposing or reacting.

But consider: Carbon dioxide (CO₂) is formed from burning carbon, but here it forms *two* new substances.

However, more importantly: Very low melting point (-182°C) → liquid or gas at room temp → likely oxygen, nitrogen, or similar gases.

But oxygen doesn't burn; it supports combustion.

Alternatively, chlorine? But chlorine is a non-metal.

But the key clue: Burns to form two new substances — this suggests a compound, because elements usually form one product when burned.

For example:
- Carbon burns → CO₂ (one product)
- Hydrogen burns → H₂O (one product)
- But if it’s a compound, e.g., methane (CH₄), it burns to form CO₂ and H₂O — two new substances.

Also, methane has a very low boiling point (~-161°C), close to -182°C.

So this matches a compound.

✔ Conclusion: Compound

> Final Table:

| Substance | Melting point °C | Electrical conductivity | Solubility in water | Effect of heating in air | Metal, non-metal or compound |
|----------|------------------|-------------------------|----------------------|----------------------------|-------------------------------|
| A | 113 | Very poor | Insoluble | Burns to form one product – an acidic gas | Non-metal |
| B | 962 | Very good | Insoluble | Loses its shiny surface | Metal |
| C | -182 | Very poor | Almost insoluble | Burns to form two new substances | Compound |

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Question 5

Match the elements to whether they are metals or non-metals, and link to one property.

List:

Elements:
- Carbon
- Mercury
- Nickel
- Sulphur
- Copper

Categories:
- Metal
- Non-metal

Properties:
- Magnetic
- Very good conductor of heat
- Brittle
- Shiny liquid
- Conductor of electricity

Now match:

#### Carbon
- Non-metal
- Property: Brittle (carbon in forms like graphite or diamond is brittle)
→ Link: Carbon → Non-metal → Brittle

#### Mercury
- Metal (only metal that is liquid at room temp)
- Property: Shiny liquid
→ Link: Mercury → Metal → Shiny liquid

#### Nickel
- Metal
- Property: Magnetic (nickel is magnetic)
→ Link: Nickel → Metal → Magnetic

#### Sulphur
- Non-metal
- Property: Brittle (sulfur is brittle solid)
→ Link: Sulphur → Non-metal → Brittle

#### Copper
- Metal
- Property: Very good conductor of heat (or conductor of electricity)
→ Link: Copper → Metal → Very good conductor of heat (or conductor of electricity)

> Note: Some properties may be shared, but only one per element is needed.

Let’s assign clearly:

| Element | Metal or non-metal | Property |
|-----------|--------------------|-------------------------------|
| Carbon | Non-metal | Brittle |
| Mercury | Metal | Shiny liquid |
| Nickel | Metal | Magnetic |
| Sulphur | Non-metal | Brittle |
| Copper | Metal | Very good conductor of heat |

> ✔ So draw lines accordingly.

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Final Answers Summary

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Q3a:

1. Good electrical conductor
2. Good thermal conductor

Q3b:

1. Electrical insulator
2. Boiling point -153°C

Q3c:

1. Melting point 3422°C
2. Good electrical conductor

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Q4 Table Completed:

| Substance | Metal, non-metal or compound |
|----------|-------------------------------|
| A | Non-metal |
| B | Metal |
| C | Compound |

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Q5 Matching:

- Carbon → Non-metal → Brittle
- Mercury → Metal → Shiny liquid
- Nickel → Metal → Magnetic
- Sulphur → Non-metal → Brittle
- Copper → Metal → Very good conductor of heat (or Conductor of electricity)

> (Note: "Conductor of electricity" applies to metals too, but "very good conductor of heat" is specific and appropriate.)

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✔ Total Marks: 35

You’ve now completed all questions correctly.

Let me know if you'd like a printable version or diagram for Q5!