Chemistry
📚 Master key facts, important dates, historical events, geographical features, and scientific discoveries that are crucial for competitive exams.
Important Facts
Study MaterialImportant Facts – Chemistry
Chemistry Important Facts help candidates quickly revise important concepts, elements, compounds, reactions, discoveries, scientific laws, and practical applications frequently asked in competitive examinations.
These facts are highly useful for UPSC, SSC, Banking, Railway, Defence, State PSC, Insurance, CDS, NDA, and various government examinations.
Basic Chemistry Facts
- Chemistry is known as the → Central Science
- Smallest particle of matter → Atom
- Smallest particle capable of independent existence → Molecule
- Anything that has mass and occupies space → Matter
- Father of Modern Chemistry → Antoine Lavoisier
- Father of Atomic Theory → John Dalton
- Electron discovered by → J. J. Thomson
- Neutron discovered by → James Chadwick
- Nucleus discovered by → Rutherford
- Proton discovered by → Goldstein
Branches of Chemistry
| Branch | Study Area |
|---|---|
| Organic Chemistry | Carbon Compounds |
| Inorganic Chemistry | Metals & Minerals |
| Physical Chemistry | Energy & Chemical Reactions |
| Analytical Chemistry | Composition Analysis |
| Biochemistry | Chemistry of Living Organisms |
Matter & Classification Facts
- Solid has → Fixed shape and volume
- Liquid has → Fixed volume but no fixed shape
- Gas has → Neither fixed shape nor volume
- Pure substances include → Elements & Compounds
- Homogeneous mixtures have → Uniform composition
- Heterogeneous mixtures have → Non-uniform composition
- Air is a → Homogeneous mixture
- Soil is a → Heterogeneous mixture
Elements & Symbols Important Facts
| Element | Symbol | Atomic Number |
|---|---|---|
| Hydrogen | H | 1 |
| Helium | He | 2 |
| Carbon | C | 6 |
| Oxygen | O | 8 |
| Sodium | Na | 11 |
| Iron | Fe | 26 |
| Silver | Ag | 47 |
| Gold | Au | 79 |
Important Chemical Compounds
- Water → H₂O
- Carbon Dioxide → CO₂
- Common Salt → NaCl
- Baking Soda → NaHCO₃
- Washing Soda → Na₂CO₃·10H₂O
- Bleaching Powder → CaOCl₂
- Marble → CaCO₃
- Ammonia → NH₃
- Methane → CH₄
- Sulphuric Acid → H₂SO₄
Acids, Bases & Salts Facts
| Type | Property | Example |
|---|---|---|
| Acid | Sour Taste | HCl |
| Base | Bitter Taste | NaOH |
| Salt | Neutral Compound | NaCl |
| Strong Acid | Highly Ionized | H₂SO₄ |
| Weak Acid | Partially Ionized | CH₃COOH |
pH Scale Important Facts
- pH less than 7 → Acidic
- pH equal to 7 → Neutral
- pH greater than 7 → Basic
- Pure water pH value → 7
- Lemon juice is → Acidic
- Soap solution is → Basic
- Litmus turns red in → Acidic medium
- Litmus turns blue in → Basic medium
Metals & Non-Metals Facts
- Mercury is the only → Liquid Metal
- Bromine is the only → Liquid Non-Metal
- Graphite conducts → Electricity
- Gold is highly → Malleable
- Silver is the best conductor of → Electricity
- Copper used in → Electric wires
- Diamond is the hardest → Natural substance
- Sodium stored in → Kerosene
Periodic Table Facts
| Fact | Information |
|---|---|
| Periodic Table developed by | Dmitri Mendeleev |
| Modern Periodic Law given by | Henry Moseley |
| Total Periods | 7 |
| Total Groups | 18 |
| Most reactive metal | Cesium |
| Most reactive non-metal | Fluorine |
Important Gases & Uses
- Oxygen supports → Combustion
- Carbon dioxide used in → Fire extinguishers
- Hydrogen is the → Lightest gas
- Nitrogen used in → Fertilizers
- Helium used in → Balloons
- Chlorine used in → Water purification
- Ozone protects Earth from → UV Rays
- LPG mainly contains → Butane & Propane
Important Chemical Reactions
| Reaction | Example |
|---|---|
| Rusting | Oxidation of Iron |
| Neutralization | Acid + Base |
| Photosynthesis | Food formation in plants |
| Respiration | Energy release process |
| Combustion | Burning process |
Everyday Chemistry Facts
- Vinegar contains → Acetic Acid
- Curd contains → Lactic Acid
- Tamarind contains → Tartaric Acid
- Ant sting contains → Formic Acid
- Toothpaste is → Basic in nature
- Baking soda used in → Cooking & Baking
- Bleaching powder used for → Disinfection
- Soap cleans because of → Micelle formation
Important Scientists & Discoveries
- Atomic Theory → John Dalton
- Periodic Table → Mendeleev
- Electron → J. J. Thomson
- Nucleus → Rutherford
- Neutron → James Chadwick
- Radioactivity → Henri Becquerel
- Radium discovery → Marie Curie
- Avogadro Hypothesis → Amedeo Avogadro
Most Important Topics Asked in Exams
- Atomic Structure
- Periodic Table
- Acids, Bases & Salts
- Chemical Formulas
- Important Compounds
- Metals & Non-Metals
- Important Gases
- pH Scale
- Chemical Reactions
- Everyday Chemistry
Quick Revision Framework
Learn Basic Concepts
↓
Remember Elements & Symbols
↓
Study Compounds & Reactions
↓
Revise Periodic Table & pH Scale
↓
Practice MCQs Daily
↓
Boost GK Preparation
Final Takeaway
Chemistry Important Facts cover atomic structure, periodic table, compounds, reactions, scientific discoveries, and practical applications frequently asked in competitive examinations.
Regular revision of chemistry facts improves General Science knowledge, memory retention, and competitive examination performance significantly.