.jpg)
Metals and Non-metals: NOTES
Metals and Non-metals
1. Introduction
- Elements in nature are broadly classified as metals and non-metals based on their properties.
- Metals are typically shiny, conductive, and malleable, while non-metals are usually dull, non-conductive, and brittle.
2. Physical Properties of Metals
- Luster: Metals have a characteristic shine or luster (except for mercury).
- Conductivity: They conduct heat and electricity well.
- Malleability and Ductility: Metals can be hammered into thin sheets (malleability) and drawn into wires (ductility).
- Density: Most metals are dense.
3. Chemical Properties of Metals
- Reaction with Oxygen: Metals generally react with oxygen to form metal oxides.
- Reaction with Water: Some metals react with water to form metal hydroxides and hydrogen gas.
- Reaction with Acids: Metals react with acids to produce salt and hydrogen gas.
4. Uses of Metals
- Metals are used extensively in industries for construction, electrical wiring, machinery, and transportation due to their strength and conductivity.
5. Physical Properties of Non-metals
- Appearance: Non-metals are usually dull and lack luster.
- Conductivity: They are poor conductors of heat and electricity.
- Brittleness: Non-metals are often brittle and break into powdery form when hammered.
6. Chemical Properties of Non-metals
- Reaction with Oxygen: Non-metals may react with oxygen to form oxides.
- Reaction with Hydrogen: Some non-metals react with hydrogen to form hydrides.
- Reaction with Acids: Non-metals generally do not react with acids.
7. Uses of Non-metals
- Non-metals find applications in various industries for insulation (e.g., rubber), as fertilizers (nitrogen), and in electronic components (e.g., silicon).
8. Metalloids
- Metalloids have properties intermediate between metals and non-metals.
- Examples include silicon, germanium, and arsenic.
- They are used in semiconductors and electronics.
9. Reactivity Series
- Metals can be arranged in order of their reactivity from most reactive to least reactive.
- This series helps predict how metals will react with other substances.
10. Extraction of Metals
- Metals are extracted from their ores through processes such as reduction using carbon or electrolysis.
- The method used depends on the reactivity of the metal.
11. Corrosion
- Metals may undergo corrosion (e.g., rusting of iron) due to their reaction with oxygen and moisture in the environment.
- Methods to prevent corrosion include painting, galvanizing, and alloying.
12. Importance of Metals and Non-metals
- Both metals and non-metals play crucial roles in our daily lives and in various industries.
- Understanding their properties helps in selecting appropriate materials for different applications.
Summary
- Metals and non-metals are fundamental categories of elements based on their properties.
- Their distinct characteristics determine their uses and applications in various fields, from construction and manufacturing to technology and everyday products.
This overview covers the essential points of the Metals and Non-metals chapter in a simple and understandable language.