Topics
Matter
- Matter (Substance)
- Characteristics of Particles (Molecules) of Matter
- States of Matter
- The Solid State
- The Liquid State
- The Gaseous State
- Kinetic Theory of Matter
- Heat and change of physical state
- Concept of Melting (Fusion)
- Concept of Evaporation
- Concept of Boiling (Vaporization)
- Concept of Condensation (Liquefaction)
- Concept of Freezing (Solidification)
- Concept of Sublimation
- Concept of Desublimation (Deposition)
- Laws of Chemical Combination
- Law of Conservation of Mass
Physical and Chemical Changes
- Changes-Physical and Chemical
- Classification of Change: Slow and Fast Changes
- Classification of Change: Natural and Man-made Changes
- Classification of Change: Periodic and Non-periodic Changes
- Classification of Change: Reversible and Irreversible Changes
- Classification of Change: Physical Changes
- Chemical Reaction
Elements, Compounds and Mixtures
- Matter (Substance)
- Natural substances
- Pure Substances
- Impure Substance
- Elements
- Types of Element: Metals
- Types of Element: Non-metal
- Type of Element: Metalloid
- Type of Elements: Noble Or Inert Gases
- Difference Between Metals, Non-metals, Metalloids, and Noble Gases
- Compound
- Mixture
- Types of Mixtures
- Formation of Mixtures
- Separation of Mixtures
- Methods of Separation
- Handpicking Method
- Magnetic Separation Method
- Gravitation Method
- Sublimation Method
- Solvent Extraction (Using a Separating Funnel Method)
- Crystallisation Method
- Sedimentation Method
- Decantation Method
- Filtration Method
- Evaporation Method
- Centrifugation Method
- Fractional Distillation Method
- Chromatography Method
- Diffusion Method
- Liquefaction Method
Atomic Structure
- Atoms: Building Blocks of Matter
- History of Atom
- Dalton’s Atomic Theory
- J. J. Thomson’s Atomic Model
- Lord Rutherford’s Atomic model
- Discovery of Charged Particles in Matter
- Electrons (e)
- Protons (p)
- Nucleus
- Neutrons (n)
- Neils Bohr’s Model of an Atom
- Structure of an Atom
- Atomic Number (Z), Mass Number (A), and Number of Neutrons (n)
- Atomic Mass
- Isotopes
- Electronic Configuration of Atom
- Electronic Configuration of Atom
- Valency
- Variable Valency
- Ions (Radicals) and Its Types
Language of Chemistry
- Language of Chemistry
- Law of Conservation of Mass
- Symbols Used to Represent Atoms of Different Elements
- Valency
- Variable Valency
- Ions (Radicals) and Its Types
- Chemical Formula or Molecular Formula
- Molecular Formula of Compounds
- Chemical Formula or Molecular Formula
- Significance of Molecular/Chemical Formulae
- Chemical Equation
- Balancing Chemical Equation
Chemical Reactions
Chemical Reaction
- Chemical Reaction
- Chemical Reaction
- Indicators of a Chemical Change (Chemical Reaction)
- Conditions Necessary for Chemical Reactions
Types of Chemical Reactions
- Types of Chemical Change or Chemical Reaction
- Direct Combination (or Synthesis) Reaction
- Decomposition Reactions
- Single Displacement Reactions
- Double Displacement Reaction
- Types of Double Displacement: Precipitation Reaction
- Types of Double Displacement: Neutralization Reaction
- Neutralization Reactions in Our Daily Life
- Reactivity Series of Metals
- Energy Change in Chemical Reactions
- Oxides
Hydrogen
- Hydrogen
- Preparation of Hydrogen
- Laboratory Preparation of Hydrogen
- Manufacture of Hydrogen
- Physical Properties of Hydrogen
- Chemical Properties of Hydrogen
- Tests for Hydrogen
- Uses of Hydrogen
- Oxidation, Reduction and Redox Reactions
Water
- Water: Our Lifeline
- Importance of Water
- Sources of Water
- Water Cycle
- Availability of Water
- Physical Properties of Water
- Anomalous Expansion of Water
- Water - a Universal Solvent
- Capacity of Water to Dissolve Substances - Saturated, Unsaturated, and Supersaturated Solutions
- Solution
- Suspension Solution
- Colloidal Solution
- Difference Between Solution, Colloidal Solution, and Suspension Solution
- Crystals and Crystallisation
- Hydrated and Anhydrous Substances
- Efflorescence, Hygroscopic, and Deliquescence Substances
- Chemical Properties of Water
- Classification of water: Soft and Hard Water
- Advantage and Disadvantage of Hard Water
- Removal of Hardness of Water
- Water Pollution and Its Causes
- Prevention of Water Pollution
- Effects of Water Pollution
- Water Management (Conservation of Water)
- Fresh Water Management
- Waste Water Management
- Water - a Universal Solvent
Carbon and Its Compounds
- Carbon: A Versatile Element
- Classification of Compounds of Carbon
Allotropy in carbon
Amorphous Forms of Carbon
- Non-crystalline/Amorphous Forms: Coal
- Non-crystalline/Amorphous Forms: Coke
- Non-crystalline/Amorphous Forms: Charcoal
- Non-crystalline/Amorphous Forms: Lamp Black (Soot)
- Non-crystalline/Amorphous Forms: Gas Carbon
Carbon Dioxide
- Carbon Dioxide
- Preparation of Carbon Dioxide
- Laboratory Preparation of Carbon Dioxide
- Properties of Carbon Dioxide
- Tests for Carbon Dioxide
- Importance of Carbon Dioxide
- Fire Extinguisher
- Carbon Dioxide
- Green House Effect
- Preventive Measures of Green House Effect
- Global Warming
- Preventive Measures of Global Warming
- Cause of Increased Percentage of Carbon Dioxide in the Atmosphere
- Steps to Balance Carbon Dioxide in the Atmosphere
Carbon Monoxide - A Compound of Carbon
- Carbon Monoxide
- Formation of Carbon Monoxide and Its Addition to the Atmosphere
- Harmful Effects of Carbon Monoxide
- Precautions and Remedies for Carbon Monoxide Poisoning
- Reducing Action of Carbon Monoxide
- Molecular Formula
- Valency
Molecular Formula:
In any compound, the elements are present in a specific ratio. This means a fixed number of atoms of each element join together to form one molecule of the compound.
The molecular formula tells us,
- The symbols of the elements in the compound.
- The number of atoms of each element is shown as subscripts.
| Sr. No. | Name of the compound | Molecular formula | Constituent elements | Number of atoms of constituent elements |
|---|---|---|---|---|
| 1 | Water | H₂O | H, O | H = 2, O = 1 |
| 2 | Hydrogen chloride | HCl | H, Cl | H = 1, Cl = 1 |
| 3 | Methane | CH₄ | C, H | C = 1, H = 4 |
| 4 | Magnesium chloride | MgCl₂ | Mg, Cl | Mg = 1, Cl = 2 |
Valency:
- Chemical Bonding: The ability of an atom to form chemical bonds with other atoms is called valency. It is a key chemical property of each atom.
- Valency Number: Valency is shown by a number, which indicates how many chemical bonds an atom can form. For example, carbon has a valency of 4, so it can form four bonds.
- Consistency of Valency: The valency of an element generally remains the same in different compounds. For example, hydrogen usually has a valency of 1, and oxygen typically has a valency of 2.
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