Metals and Non-Metals Study Notes

Introduction

• Classification of materials into metals and non-metals.

Metals

Definition and Characteristics

• Metals are sonorous (produce sound when hit).
• Examples in daily life: Gold (a mixture with copper or silver), aluminum, iron.

Properties of Metals

1. Physical Properties:
   • Lustrous: Shiny appearance (e.g., gold).
   • Malleable: Can be beaten into sheets (e.g., aluminum foil).
   • Ductile: Can be drawn into wires (e.g., copper wires).
   • Hard: Generally hard, except sodium and potassium which are soft.
   • Sonorous: Produces sound when struck.
2. Conductivity:
   • Good conductors of heat and electricity.

Examples of Metals

• Common metals: Iron, copper, aluminum, calcium, magnesium.
• Copper is widely used in electrical wiring due to its ductility and conductivity.

Non-Metals

Definition and Characteristics

• Non-metals have opposite properties of metals.

Properties of Non-Metals

1. Physical Properties:

   • Dull appearance: Non-lustrous.
   • Soft: Generally softer than metals except for diamonds (hardest known substance).
   • Non-malleable: Break down into a powdery mass.
   • Non-sonorous: Do not produce sound when struck.

2. Conductivity:

   • Poor conductors of heat and electricity.

Examples of Non-Metals

• Common non-metals: Carbon, sulfur, oxygen, phosphorus.

Exceptions

• Exception of metals:
  • Sodium and potassium are soft, can be cut with a knife.
  • Mercury is a liquid metal.
• Exception of non-metals:
  • Only liquid non-metal is bromine.

Chemical Properties

Reactions with Oxygen

• Metals generally react with oxygen to form oxides.
• Example: Iron rusts when exposed to moisture and oxygen, forming Fe2O3.XH2O (rust).
• Magnesium burns in the presence of oxygen to form magnesium oxide (MgO).

Nature of Oxides

• Metallic Oxides: Basic in nature, turn red litmus blue.
• Non-Metallic Oxides: Acidic in nature, turn blue litmus red.

Reactions with Water

• Sodium: Reacts vigorously with water, producing sodium hydroxide (NaOH) and hydrogen gas.
• Iron: Reacts slowly with water.
• Phosphorus: Non-metal, does not react with water.

Reactions with Acids

• Metals react with acids to produce hydrogen gas.
  • Example: Zinc + sulfuric acid → zinc sulfate + hydrogen gas.
• Non-metals do not react with acids.

Displacement Reactions

• A more reactive metal can displace a less reactive metal.
• Example: Zinc displacing copper from copper sulfate solution.

Uses of Metals and Non-Metals

• Metals: Used for making machinery, bridges, and electrical wiring.
• Non-Metals: Used in fertilizers (nitrogen, phosphorus), purification of water (chlorine), and as antiseptics (iodine).

Summary of Key Differences Between Metals and Non-Metals

| Property | Metals | Non-Metals | |------------------|--------------------------|--------------------------| | Appearance | Lustrous | Dull | | Hardness | Generally hard | Generally soft | | Malleability | Malleable | Non-malleable | | Ductility | Ductile | Non-ductile | | Conductivity | Good conductors | Poor conductors |

Activities and Experiments

• Sound Activity: Compare sound produced by metal vs. wood.
• Electric Circuit Experiment: Prove conductivity of metals (bulb will glow with metal, not with non-metals).
• Rust Testing: Dissolve rust and test solutions with litmus paper.
• Burning Magnesium: Demonstrate formation of magnesium oxide.
• Reaction with Sodium: Observe the vigorous reaction of sodium with water.

Conclusion

• Reviewed the physical and chemical properties of metals and non-metals, along with practical applications and activities to enhance understanding.