1. General Information
- Symbol: Al
- Atomic Number: 13
- Atomic Mass: 26.98 u
- Group: 13 (Boron Group)
- Period: 3
- Block: p-block
- Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p¹
- Valence Electrons: 3
- Phase at Room Temperature: Solid
2. Isotopes of Aluminium
| Isotope |
Protons |
Neutrons |
Abundance |
Notes |
| ²⁷Al |
13 |
14 |
100% |
Only stable isotope. |
| ²⁶Al |
13 |
13 |
Trace |
Radioactive, used in dating meteorites. |
3. Physical Properties
- Color: Silvery-white
- Odor: Odorless
- Density: 2.70 g/cm³
- Melting Point: 660.3°C
- Boiling Point: 2,470°C
- State at STP: Solid
- Lightweight and Ductile – Can be easily shaped and drawn into wires.
4. Chemical Properties
- Highly Reactive (Forms Oxide Layer):
- Reacts with oxygen to form aluminium oxide (Al₂O₃), creating a protective layer that prevents further corrosion.
- Amphoteric Nature:
- Reacts with both acids and bases.
- Good Conductor of Heat and Electricity.
- Non-Magnetic and Non-Sparking.
Reaction with Oxygen:
4Al + 3O₂ → 2Al₂O₃
Reaction with Hydrochloric Acid:
2Al + 6HCl → 2AlCl₃ + 3H₂↑
Reaction with Sodium Hydroxide:
2Al + 2NaOH + 6H₂O → 2Na[Al(OH)₄] + 3H₂↑
5. Occurrence and Abundance
- Third most abundant element in Earth’s crust (8.1%).
- Never found free in nature – Occurs in compounds.
- Common Ores:
- Bauxite (Al₂O₃·xH₂O) – Primary source of aluminium.
- Cryolite (Na₃AlF₆) – Used in aluminium extraction.
6. Industrial Production of Aluminium
7. Uses of Aluminium
| Application |
Description |
| Aerospace and Automotive |
Lightweight parts for fuel efficiency. |
| Construction |
Window frames, roofing, and structural components. |
| Packaging |
Foil, cans, and beverage containers. |
| Electrical Industry |
Power lines and cables (light and conductive). |
| Consumer Goods |
Laptops, smartphones, and appliances. |
| Transportation |
High-speed trains and marine vessels. |
| Medical Equipment |
Lightweight surgical tools and equipment. |
8. Important Aluminium Compounds
| Compound |
Formula |
Use |
| Aluminium Oxide |
Al₂O₃ |
Abrasives, ceramics, refractories. |
| Aluminium Hydroxide |
Al(OH)₃ |
Antacid, fire retardant. |
| Aluminium Sulfate |
Al₂(SO₄)₃ |
Water treatment, paper industry. |
| Aluminium Chloride |
AlCl₃ |
Catalysts in chemical reactions. |
| Aluminium Nitrate |
Al(NO₃)₃ |
Waterproofing textiles, corrosion prevention. |
9. Biological Role of Aluminium
- No known biological role in humans.
- Non-toxic in small amounts, but excessive exposure may lead to health concerns.
- Used in Medicine:
- Antacids and vaccines (as aluminium salts).
10. Aluminium in Environmental Chemistry
- Recyclable: 75% of aluminium ever produced is still in use.
- Eco-Friendly: Reduces energy consumption by 95% when recycled.
- Environmental Concerns:
- Bauxite mining can cause deforestation and soil erosion.
- Aluminium oxide dust can irritate the respiratory system.
11. Safety and Hazards
- Stable in Air due to the oxide layer.
- Fine Aluminium Dust is Flammable and can explode.
- Health Risks:
- Prolonged exposure to aluminium dust can lead to lung issues.
- Aluminium toxicity is rare but can affect the nervous system.
Handling Precautions:
- Store in a dry place to avoid corrosion.
- Handle aluminium dust carefully to prevent fire hazards.
Fun Facts About Aluminium:
- Discovered in 1825 by Hans Christian Ørsted.
- Once more valuable than gold due to the difficulty of extraction.
- The cap of the Washington Monument is made of pure aluminium.
- Aluminium is used in spacecraft due to its strength-to-weight ratio.