Educational worksheet on metals and non-metals with questions and illustrations.

Here is the solution to the worksheet "Materials – Metals and Non-Metals Worksheet -1":

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Worksheet: Materials – Metals and Non-Metals

#### 1. The most ductile metal.
- Answer: Gold (Au)
- Explanation: Gold is the most ductile metal, meaning it can be stretched into thin wires without breaking.

#### 2. The most malleable metal.
- Answer: Gold (Au)
- Explanation: Gold is also the most malleable metal, meaning it can be hammered into thin sheets without breaking.

#### 3. The metal which is the best conductor of electricity.
- Answer: Silver (Ag)
- Explanation: Silver has the highest electrical conductivity among all metals. However, it is often not used extensively due to its high cost.

#### 4. The non-metal which is a good conductor of electricity.
- Answer: Graphite
- Explanation: Graphite is a form of carbon that conducts electricity well due to the delocalized electrons in its structure.

#### 5. The hardest known substance.
- Answer: Diamond
- Explanation: Diamond is the hardest naturally occurring substance, composed of carbon atoms arranged in a rigid crystal lattice.

#### 6. Name three non-metals which have lustre.
- Answer: Graphite, Iodine, Selenium
- Explanation:
- Graphite: Shiny due to its layered structure.
- Iodine: Forms shiny crystals.
- Selenium: Has a metallic luster.

#### 7. The metal which exists in liquid state at room temperature.
- Answer: Mercury (Hg)
- Explanation: Mercury is the only metal that is liquid at room temperature.

#### 8. The non-metal which exists in liquid state at room temperature.
- Answer: Bromine (Br₂)
- Explanation: Bromine is a non-metal that exists as a liquid at room temperature.

#### 9. The metal which is a poor conductor of heat.
- Answer: Lead (Pb)
- Explanation: Lead is a relatively poor conductor of heat compared to other metals like copper or silver.

#### 10. The metal which is the best conductor of heat.
- Answer: Silver (Ag)
- Explanation: Silver is the best conductor of heat among metals, similar to its high electrical conductivity.

#### 11. Name two non-metals which exist in gaseous state.
- Answer: Hydrogen (H₂), Oxygen (O₂)
- Explanation: Both hydrogen and oxygen are non-metals that exist as gases at room temperature.

#### 12. Name two non-metals which exist in solid state.
- Answer: Carbon (in diamond or graphite form), Silicon
- Explanation:
- Carbon: Exists as solids like diamond and graphite.
- Silicon: A solid non-metal used extensively in electronics.

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Final Answer:

1. Gold (Au)
2. Gold (Au)
3. Silver (Ag)
4. Graphite
5. Diamond
6. Graphite, Iodine, Selenium
7. Mercury (Hg)
8. Bromine (Br₂)
9. Lead (Pb)
10. Silver (Ag)
11. Hydrogen (H₂), Oxygen (O₂)
12. Carbon, Silicon

Boxed Final Answer:
\[
\boxed{
\begin{array}{l}
1. \text{Gold (Au)} \\
2. \text{Gold (Au)} \\
3. \text{Silver (Ag)} \\
4. \text{Graphite} \\
5. \text{Diamond} \\
6. \text{Graphite, Iodine, Selenium} \\
7. \text{Mercury (Hg)} \\
8. \text{Bromine (Br₂)} \\
9. \text{Lead (Pb)} \\
10. \text{Silver (Ag)} \\
11. \text{Hydrogen (H₂), Oxygen (O₂)} \\
12. \text{Carbon, Silicon}
\end{array}
}
\]