Metals, Non-metals, Carbon Compounds and Everyday Chemistry
Metals, Non-metals, Carbon Compounds and Everyday Chemistry
This topic gathers the most fact-heavy chemistry: properties and exceptions of metals and non-metals, the reactivity series and ores, alloys, allotropes of carbon and polymers, and the chemistry of daily life (soaps, fuels, common chemical names). NTPC asks one-line questions here, so tables are the whole game.
1. Metals, Non-metals and Ores
| Fact | Detail |
|---|---|
| Reactivity series (high to low) | K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Hg, Ag, Au |
| Exceptions | Mercury is a liquid metal; sodium and potassium are soft; graphite is a non-metal that conducts electricity; iodine is lustrous |
| Best conductors | Silver, then copper |
| Most abundant metal in the crust | Aluminium |
| Most abundant element in the crust | Oxygen |
| Noble metals | Gold, platinum, silver; resist corrosion |
| Bauxite | Ore of aluminium |
| Haematite, magnetite | Ores of iron |
| Cinnabar | Ore of mercury |
| Galena | Ore of lead |
| Calamine, zinc blende | Ores of zinc |
| Galvanisation | Coating iron with zinc to prevent rusting |
2. Alloys and Carbon
| Alloy | Composition |
|---|---|
| Brass | Copper and zinc |
| Bronze | Copper and tin |
| Stainless steel | Iron, chromium, nickel (and carbon) |
| Solder | Lead and tin |
| Duralumin | Aluminium, copper, magnesium, manganese |
| Amalgam | Any alloy of mercury |
| Carbon item | Fact |
|---|---|
| Allotropes | Diamond, graphite, fullerene (C-60), graphene |
| Diamond | Hardest natural substance; each carbon bonded to four others; does not conduct |
| Graphite | Layers that slide; used in pencils and as a lubricant; conducts electricity |
| Catenation | Carbon's ability to form long chains |
| Hydrocarbons | Alkanes (single bonds, CₙH₂ₙ₊₂), alkenes (double), alkynes (triple) |
| Polymers | PVC, polythene, nylon (first fully synthetic fibre), Teflon (non-stick), Bakelite (thermosetting) |
3. Everyday Chemistry
| Substance | Fact |
|---|---|
| LPG | Mainly butane and propane; ethyl mercaptan added for smell |
| CNG | Mainly methane |
| Biogas | Mainly methane |
| Soap | Sodium or potassium salt of long-chain fatty acids; antiseptic soaps use agents such as bithional |
| Detergents | Work in hard water too |
| Hard water | Due to calcium and magnesium salts |
| Laughing gas | Nitrous oxide, N₂O |
| Dry ice | Solid carbon dioxide |
| Vinegar | 5 to 8% acetic acid |
| Common salt in iodised form | Fights goitre |
✗ Brass is an alloy of copper and tin | ✓ Brass is copper and zinc; bronze is copper and tin
✗ Graphite is a metal because it conducts electricity | ✓ Graphite is a non-metal (an allotrope of carbon) that conducts electricity
हिंदी नोट: पीतल तांबा और जस्ता, कांसा तांबा और टिन तथा सोल्डर सीसा और टिन का मिश्रधातु है। हीरा, ग्रेफ़ाइट और फुलरीन कार्बन के अपररूप हैं। बॉक्साइट एल्युमिनियम का अयस्क है। LPG मुख्यतः ब्यूटेन और प्रोपेन तथा CNG मुख्यतः मीथेन है।
Exam Pointer: Verified NTPC patterns: an allotrope of carbon (January 2021 CBT-1) and the compound that gives soap its antiseptic property (April 2016 CBT-1). Alloy, ore and reactivity questions are tagged syllabus-based.
Pariksha Pattern: Every Way NTPC Asks This Topic
Pattern 1: Allotropes and carbon compounds
[PYQ: NTPC CBT-1 7-Jan-2021 Shift-1]
EXAM LEVEL
Q. Which allotrope of carbon is used in pencils, and why can it act as a lubricant?
Graphite. Its carbon atoms are in layers held weakly to each other, so the layers slide.
Answer: Graphite; sliding layers
EXAMATLAS LEVEL
Q. Which is the hardest natural substance, which allotrope of carbon has 60 atoms shaped like a football, and what is the general formula of alkanes?
Diamond is the hardest natural substance. Buckminsterfullerene (C-60) is the football-shaped allotrope. Alkanes have the formula CₙH₂ₙ₊₂.
Answer: Diamond; fullerene C-60; CₙH₂ₙ₊₂
Pattern 2: Everyday chemistry: soaps, fuels and common names
[PYQ: NTPC CBT-1 7-Apr-2016 Shift-3]
EXAM LEVEL
Q. What is the main component of CNG?
Methane.
Answer: Methane
EXAMATLAS LEVEL
Q. Why do detergents work in hard water while soap does not? Which gas is called laughing gas, and why is a strong-smelling compound added to LPG?
Soap forms an insoluble scum with calcium and magnesium ions in hard water; detergents do not. Laughing gas is nitrous oxide (N₂O). LPG has no smell, so ethyl mercaptan is added to detect leaks.
Answer: Soap forms scum; nitrous oxide; leak detection
Pattern 3: Alloys and their composition
[Pattern: syllabus-based, PYQ-style]
EXAM LEVEL
Q. Solder is an alloy of which two metals?
Lead and tin.
Answer: Lead and tin
EXAMATLAS LEVEL
Q. Which pair is wrongly matched: bronze and copper-tin, brass and copper-zinc, stainless steel and iron-chromium-nickel, duralumin and copper-tin?
Duralumin is mainly aluminium with copper, magnesium and manganese. The other pairs are correct.
Answer: Duralumin and copper-tin
Pattern 4: Reactivity series, properties and ores
[Pattern: syllabus-based, PYQ-style]
EXAM LEVEL
Q. Which metal is a liquid at room temperature?
Mercury.
Answer: Mercury
EXAMATLAS LEVEL
Q. Arrange in decreasing reactivity: copper, sodium, iron, gold. Name the ore of aluminium and the process that coats iron with zinc.
Sodium is most reactive, then iron, then copper, then gold. Bauxite is the ore of aluminium. Coating iron with zinc is galvanisation.
Answer: Na, Fe, Cu, Au; bauxite; galvanisation
60-Second Revision
- Reactivity: K Na Ca Mg Al Zn Fe Pb H Cu Hg Ag Au.
- Brass Cu-Zn; bronze Cu-Sn; solder Pb-Sn; stainless steel Fe-Cr-Ni.
- Carbon allotropes: diamond (hardest), graphite (pencil, conducts), fullerene C-60.
- LPG butane-propane; CNG methane; laughing gas N₂O; dry ice solid CO₂.
Next Step: Chemistry done. Practise these one-liners in the ExamAtlas RRB NTPC 2026 mock tests; chemistry facts repeat across every NTPC cycle.