Metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine. They are one of the three major types of materials, along with polymers and ceramics. Metals are widely used in various industries and have a number of unique properties that make them highly valuable.

Properties of Metals:
1. Hardness: Metals are generally hard substances. They have a high tensile strength and can withstand external forces without breaking or deforming easily. This property makes them suitable for construction, manufacturing, and other heavy-duty applications.

2. Conductivity: Metals are excellent conductors of heat and electricity. They have a high thermal and electrical conductivity, allowing them to transfer heat and electricity efficiently. This property is utilized in electrical wiring, power transmission, and various heating applications.

3. Lustre or Shine: Metals have a characteristic lustre or shine, which is due to their ability to reflect light. This property makes them visually appealing and is often enhanced through polishing or plating.

4. Ductility and Malleability: Metals are both ductile and malleable. Ductility refers to their ability to be drawn into wires, while malleability refers to their ability to be hammered or rolled into thin sheets. These properties make metals highly versatile and easily formable into different shapes and sizes.

5. High Melting and Boiling Points: Metals generally have high melting and boiling points, which means they can withstand high temperatures without melting or vaporizing. This property makes them suitable for applications that involve high heat, such as in furnaces or engines.

Uses of Metals:
- Construction: Metals like steel and aluminum are widely used in construction for structural purposes due to their strength and durability.
- Electrical and Electronics: Metals such as copper and aluminum are used for electrical wiring and components due to their high conductivity.
- Transportation: Metals like iron and steel are used in the automotive and aerospace industries for their strength and ability to withstand high stress.
- Packaging: Metals like aluminum are used for packaging purposes due to their lightweight, corrosion resistance, and ability to be easily formed.
- Jewelry and Decoration: Precious metals like gold, silver, and platinum are used in jewelry and decorative items due to their aesthetic appeal and rarity.

In conclusion, metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine. They possess unique properties that make them essential in various industries and have a wide range of applications.

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