1. General Information
- Symbol: Mg
- Atomic Number: 12
- Atomic Mass: 24.305 u
- Group: 2 (Alkaline Earth Metals)
- Period: 3
- Block: s-block
- Electron Configuration: 1s² 2s² 2p⁶ 3s²
- Valence Electrons: 2
- Phase at Room Temperature: Solid
2. Isotopes of Magnesium
| Isotope |
Protons |
Neutrons |
Abundance |
Notes |
| ²⁴Mg |
12 |
12 |
79% |
Most abundant. |
| ²⁵Mg |
12 |
13 |
10% |
Stable. |
| ²⁶Mg |
12 |
14 |
11% |
Stable, used in dating rocks. |
3. Physical Properties
- Color: Silvery-white
- Odor: Odorless
- Density: 1.74 g/cm³
- Melting Point: 650°C
- Boiling Point: 1,090°C
- State at STP: Solid
- Lightweight and Malleable – Can be easily shaped and machined.
4. Chemical Properties
- Highly Reactive (Especially with Water and Acids):
- Reacts slowly with cold water and vigorously with hot water.
- Burns with a bright white flame when ignited.
- Forms a Protective Oxide Layer (MgO): Prevents further corrosion.
- Reacts with Oxygen: Forms magnesium oxide (MgO).
Reaction with Water:
Mg + 2H₂O → Mg(OH)₂ + H₂↑
5. Occurrence and Abundance
- Eighth most abundant element in Earth’s crust.
- On Earth:
- Found in Minerals: Dolomite (CaMg(CO₃)₂), Magnesite (MgCO₃), and Olivine.
- Seawater: Contains magnesium chloride (MgCl₂).
- In the Human Body: Present in bones and cells, crucial for biochemical reactions.
6. Industrial Production of Magnesium
7. Uses of Magnesium
| Application |
Description |
| Aerospace and Automotive |
Lightweight alloys reduce vehicle weight. |
| Construction |
Used in structural alloys and beams. |
| Medicine |
Magnesium supplements and antacids. |
| Fireworks and Flares |
Burns with bright white light. |
| Electronics |
Laptop and camera casings. |
| Biological |
Essential for muscle function and energy production. |
| Batteries |
Used in magnesium-ion batteries. |
8. Important Magnesium Compounds
| Compound |
Formula |
Use |
| Magnesium Oxide |
MgO |
Refractory bricks, insulation. |
| Magnesium Hydroxide |
Mg(OH)₂ |
Antacid, laxative (milk of magnesia). |
| Magnesium Sulfate |
MgSO₄ |
Epsom salt, muscle relaxation. |
| Magnesium Chloride |
MgCl₂ |
De-icing, dust control, supplements. |
| Magnesium Carbonate |
MgCO₃ |
Gym chalk, food additive. |
9. Biological Importance of Magnesium
- Essential for Life:
- Involved in Over 300 Enzymatic Reactions.
- Critical for ATP (energy) production and muscle function.
- Bone Health:
- 60% of the body’s magnesium is stored in bones.
- Daily Requirement:
- Men: 400-420 mg/day
- Women: 310-320 mg/day
- Deficiency Symptoms: Muscle cramps, fatigue, and irregular heartbeat.
10. Magnesium in Environmental Chemistry
11. Safety and Hazards
- Highly Flammable: Burns intensely at high temperatures.
- Water Reaction: Can generate hydrogen gas, posing explosion risks.
- Handling Precautions:
- Store in a dry, cool place.
- Use protective gloves when handling.
- Avoid exposing to open flames.