Metallic Elements & Alloys
Introduction to Metallic Elements & Alloys
Metals are elements characterized by their luster, high electrical and thermal conductivity, and malleability. Alloys, which are mixtures of metals, are engineered to enhance specific properties like strength or corrosion resistance.
Classification: High-Performance Metals
- Noble Metals: Highly resistant to oxidation and corrosion (Gold, Platinum, Silver).
- Alkali Metals: Highly reactive metals found in the first column of the periodic table (Lithium, Sodium, Potassium).
- Industrial Metals: The workhorses of modern infrastructure (Iron, Aluminium, Copper).
The Metal & Alloy Master Table
| Metal / Alloy | Primary Component(s) | Key Feature / Usage |
|---|---|---|
| Gold | Pure Element (Au) | Most malleable and ductile metal |
| Silver | Pure Element (Ag) | Best conductor of electricity |
| Mercury | Pure Element (Hg) | Only metal liquid at room temperature |
| Aluminium | Pure Element (Al) | Most abundant metal in Earth's crust |
| Brass | Copper + Zinc | Musical instruments & hardware |
| Bronze | Copper + Tin | Statues, coins, and medals |
| Stainless Steel | Iron + Chromium | Resistant to rusting and corrosion |
| Amalgam | Mercury + Other metals | Dental fillings |
| Solder | Lead + Tin | Low melting point; used for joints |
Key Scientific Facts
- Galvanization is the process of coating Iron or Steel with a layer of Zinc to prevent rusting.
- Tungsten has the highest melting point of all pure metals (~3422°C), making it ideal for light bulb filaments.
- Rusting is a chemical reaction (oxidation) that requires both Oxygen and Moisture.
- Haemoglobin in human blood contains Iron as its central atom, while Chlorophyll in plants contains Magnesium.
- Duralumin is a lightweight aluminium alloy used extensively in the manufacturing of aircraft.
Subject Card Prompts (Flashcards)
- Q: Which metal is the best conductor of electricity?
- A: Silver (Ag).
- Q: What is the composition of the alloy Brass?
- A: Copper and Zinc.
- Q: Which metal is known as "Liquid Silver"?
- A: Mercury.
- Q: Which is the hardest naturally occurring substance?
- A: Diamond (Note: It is a non-metal, an allotrope of Carbon).
Practice MCQ
"Which of the following metals is used in the manufacture of aircraft bodies because of its lightweight and strength?"
A) Iron
B) Copper
C) Aluminium
D) Lead
(Correct: C - Aluminium)