Explain the composition, Properties and applications of the following materials

a) Silica (SiO₂)

• Composition:
  Silicon dioxide (SiO₂), found naturally in quartz, sand, and rocks.
• Properties:
  • High melting point
  • High hardness
  • Chemically inert
  • Good electrical insulator
  • Excellent thermal stability
• Applications:
  • Glass manufacturing
  • Ceramics and cement
  • Electronics (silicon chips)
  • Filler in paints, plastics, and rubbers
  • Catalyst and support in chemical processes

b) Ceramics

• Composition:
  Inorganic, non-metallic solids made from clay, minerals, oxides, nitrides, or carbides.
• Properties:
  • Hard and strong
  • High compressive strength
  • Excellent thermal resistance
  • Chemically inert
  • Electrical insulators
  • Brittle nature
• Applications:
  • Tiles, pottery, and art
  • Heat-resistant linings (furnaces, kilns)
  • Electrical insulators
  • Biomedical implants
  • Cutting tools and machine parts

c) Glass

• Composition:
  Silica (SiO₂) + Soda ash (Na₂CO₃) + Lime (CaO), melted and cooled rapidly.
• Properties:
  • Transparent
  • Hard and durable
  • Chemically resistant
  • Smooth and easy to clean
  • Amorphous (non-crystalline structure)
  • Resistant to thermal shock (in borosilicate variants)
• Applications:
  • Windows, mirrors, lenses
  • Laboratory equipment
  • Cookware (e.g., Pyrex)
  • Optical fibers
  • Medical instruments

d) Graphite

• Composition:
  Allotropic form of carbon with hexagonal layers of atoms.
• Properties:
  • Good electrical conductor
  • Excellent lubricant
  • High thermal stability
  • Chemically inert
  • Soft and slippery
  • Lightweight
• Applications:
  • Electrodes (batteries, arc lamps)
  • Lubricants in machinery
  • Crucibles and furnace linings
  • Pencil leads
  • Carbon fiber composites (aerospace, sports gear)

e) Diamond

• Composition:
  Pure crystalline carbon with a tetrahedral (3D) lattice.
• Properties:
  • Hardest known natural material
  • High thermal conductivity
  • Electrical insulator
  • Chemically inert
  • Transparent with high refractive index (sparkling)
• Applications:
  • Cutting, drilling, and grinding tools
  • Jewelry
  • Thermal heat spreaders in electronics
  • Optical components in lasers
  • High-pressure industrial applications

f) Polymers

• Composition:
  Long-chain molecules formed from repeating monomers (e.g., polyethylene, PVC, nylon).
• Properties:
  • Flexible and moldable
  • Lightweight
  • High tensile strength
  • Resistant to chemicals and corrosion
  • Can be engineered for heat/radiation resistance
  • Can be biocompatible
• Applications:
  • Packaging (plastic bags, bottles)
  • Automotive and aerospace parts
  • Medical devices (catheters, implants)
  • Electrical insulation
  • Household goods (furniture, containers)