Topics
Chemical Substances - Nature and Behaviour (Chemistry)
Chemical Reactions and Equations
- Chemical Equation
- Balancing Chemical Equation
- Types of Chemical Change or Chemical Reaction
- Direct Combination (or Synthesis) Reaction
- Decomposition Reactions
- Single Displacement Reactions
- Double Displacement Reaction
- Oxidation, Reduction and Redox Reactions
- Corrosion of Metals
- Rancidity of Food and Its Prevention
World of Living (Biology)
Acids, Bases and Salts
- Acids
- Bases (Alkalis)
- Indicators
- Properties of Acids
- Properties of Bases (Alkalis)
- Acid or a Base in a Water Solution
- Similarities and Differences Between Acids and Bases
- Strength of Acidic or Basic Solutions
- Salts
- Important Salts in Daily Life
- Preparation and Uses of Sodium Hydroxide
- Preparation and Uses of Bleaching Powder
- Preparation and Uses of Baking Soda
- Preparation and Uses of Washing Soda
- Preparation and Uses of Plaster of Paris
Metals and Non Metals
- Types of Element: Metals
- Physical Properties of Metals
- Chemical Properties of Metal
- Types of Element: Non-metal
- Physical Properties of Non-metal
- Chemical Properties of Non-metal
- Ionic or Electrovalent Bond
- Reactivity Series of Metals
- Extraction of Reactive Metals
- Refining of Metals
- Corrosion of Metals
- The Covalent Bond
- Prevention of Corrosion
Natural Phenomena (Physics)
Carbon and its Compounds
- Carbon: A Versatile Element
- The Covalent Bond
- Saturated and Unsaturated Carbon Compounds
- Allotropy and Allotropes of Carbon
- Crystalline Allotropes of Carbon: Diamond
- Crystalline Allotropes of Carbon: Graphite
- Crystalline Allotropes of Carbon: Fullerene
- Chains, Branches and Rings of Carbon Compound
- Functional Groups in Carbon Compounds
- Homologous Series of Carbon Compound
- Nomenclature of Organic Compounds
- Properties of Carbon
- Ethanol
- Ethanoic Acid
- Soap
- Detergents
- Cleansing Action of Soap
Effects of Current (Physics)
Life Processes
- Nutrients and Nutrition
- Mode of Nutrition in Plant
- Autotrophic Plants
- Heterotrophic Plants
- Different Ways of Taking Food
- Human Digestive System
- The Mouth and Buccal Cavity
- The Teeth and Its Structure
- The Salivary Glands
- Swallowing and Peristalsis
- The Food Pipe/Oesophagus
- The Stomach
- The Small Intestine
- Pancreas
- Absorption of Food
- The Large Intestine
- Assimilation of Food
- Liver
- Respiration
- Respiration
- Breathing in Other Animals
- Osmoregulation
- Human Respiratory System
- Circulation in Animals
- Blood
- Composition of Blood: Plasma (The Liquid Portion of Blood)
- Composition of Blood: Red Blood Cells (Erythrocytes)
- Composition of Blood: White Blood Cells (Leukocytes)
- Composition of Blood: Blood Platelets (Thrombocytes)
- Blood Circulatory System in Human
- Human Heart
- Blood Vessels
- Circulation of Blood in the Heart (Functioning of Heart)
- Types of Closed Circulation
- Heart Beat - Heart Sounds "LUBB" and "DUP"
- Function of Platelets - Clotting of Blood (Coagulation)
- Lymph and Lymphatic System
- Blood Pressure (B.P.)
- Transport System in Plants
- Water absorbing organ
- Translocation of Water (Ascent of Sap)
- Transport of Mineral Ions
- Transport of Food
- Transpiration
- Excretion
- Human Excretory System
- Function of the Kidney - “Production of Urine”
- Excretion
Natural Resources
Periodic Classification of Elements
- History of Periodic Table: Early Attempts at the Classification of Elements
- Dobereiner’s Triads
- Newland's Law of Octaves
- Mendeleev’s Periodic Table
- Merits and Demerits of Mendeleev’s Periodic Table
- The Modern Periodic Table
- Periodic Properties
- Valency
- Atomic Radius Or Atomic Size
- Metallic and Non-metallic Characters
Control and Co-ordination
- Control and Co-ordination in Human Being
- Human Nervous System
- Neuron (Or Nerve Cell) and Its Types
- Neuron (Or Nerve Cell) and Its Types
- Nerve Fibres
- Major Division of the Nervous System
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
- The Human Brain - Forebrain
- The Human Brain - Forebrain
- Reflex and Reflex Action
- Nervous Pathways in Reflexes
- Reflex Arc
- Coordination in Plant: Tropism in Plants
- Chemical Coordination
- Plant Hormones
- Types of Plant Hormones: Auxins
- Types of Plant Hormones: Gibberellins
- Types of Plant Hormones: Ethylene
- Types of Plant Hormones: Cytokinins
- Types of Plant Hormones: Abscisic Acid (ABA)
- Types of Plant Hormones: Ethylene
- Hormones in Animals
- Human Endocrine System
- Pituitary Gland or Hypophysis Gland
- Thyroid Gland
- Parathyroid Gland
- Pancreas (Islets of Langerhans)
- Adrenal Gland (Suprarenal Gland)
- Reproductive Glands (Gonads)
- Thymus Gland
Internal assessment
How do Organisms Reproduce?
Heredity
Light - Reflection and Refraction
- Reflection of Light
- Law of Reflection of Light
- Mirrors
- Plane Mirror
- Spherical Mirrors
- Rules for the Construction of Image Formed by a Spherical Mirror
- Images Formed by Spherical Mirrors
- Concave Mirror
- Image Formation by Concave Mirror
- Convex Mirror
- Image Formation by Convex Mirror
- Sign Convention
- Mirror Equation/Formula
- Linear Magnification (M) Due to Spherical Mirrors
- Introduction to Refraction of Light
- Refraction of Light Through a Rectangular Glass Slab
- Refractive Index
- Spherical Lens
- Images Formed by Sperical Lenses
- Guideline for Image Formation Due to Refraction Through a Convex and Concave Lens
- Concave Lens
- Images Formed by Concave Lenses
- Convex Lens
- Images Formed by Convex Lenses
- Sign Convention
- Lens Formula
- Magnification Due to Spherical Lenses
- Power of a Lens
The Human Eye and the Colourful World
- Human Eye
- Working of the Human Eye
- Eye Defect and Its Correction: Myopia Or Near-sightedness
- Eye Defect and its Correction: Hypermetropia or Far-sightedness
- Eye Defect and Its Correction: Presbyopia
- Care of the Eyes
- Refraction of Light Through a Prism
- Prism
- Dispersion of Light Through Prism and Formation of Spectrum
- Atmospheric Refraction
- Application of Atmospheric Refraction
- Scattering of Light and Its Types
- Applications of Scattering of Light
Electricity
- Electricity
- Electric Current
- Electric Circuit
- Potential and Potential Difference
- Symbols and Functions of Various Components of an Electric Circuits
- Ohm's Law (V = IR)
- Factors Affecting the Resistance of a Conductor
- Electrical Resistivity and Electrical Conductivity
- Resistors in Series
- Resistors in Parallel
- Effects of Electric Current
- Heating Effect of Electric Current
- Electrical Power
Magnetic Effects of Electric Current
- Magnetic Effect of Electric Current
- Magnetic Field
- Properties of magnetic lines of force
- Magnetic Field Due to a Current Carrying Straight Conductor
- Right-hand Thumb Rule
- Magnetic Field Due to Current in a Loop (Or Circular Coil)
- Magnetic Field Due to a Current Carving Cylindrical Coil (or Solenoid)
- Force on a Current Carrying Conductor in a Magnetic Field
- Electric Motor
- Electromagnetic Induction
- Faraday's Laws of Electromagnetic Induction
- Electric Generator
- Alternating Current (A.C.) Generator
- Direct Current Motor
- Household Electrical Circuits
- Distinction Between an A.C. Generator and D.C. Motor
- Types of Current
Our Environment
Sources of Energy
Sustainable Management of Natural Resources
- Sustainability of Natural Resources
- Case Study: Ganga Pollution and Ganga Action Plan
- Solid Waste Management
- Five R’s of Waste Management
- Protecting our environment
- Forests: Our Lifeline
- Stakeholders of Forest
- Conservation of Forest
- Conservation of Wildlife
- Water Management (Conservation of Water)
- Fresh Water Management
- Non-crystalline/Amorphous Forms: Coal
- Petroleum
- Conservation of Coal, Petroleum, and Natural Resources
- Overview of Natural Resource Management
- Introduction
- Occurrence of Carbon
- Characteristics of Carbon
Introduction
Carbon was discovered by Antoine Lavoisier and is one of the most abundant elements on Earth. It exists in both free form and in combination with other elements. Unlike most elements, carbon can bond with itself and other elements to create simple molecules like methane and complex structures like DNA. All living structures are carbon-based.
- Symbol of carbon: C
- Atomic number: 6
- Atomic mass: 12
- Electron configuration: 2, 4
- Valency: 4
- Non-metallic element
Carbon is found in the earth's crust in the form of carbonate, coal, and petroleum, which contribute around 0.27%. Carbon dioxide is approximately 0.03% of the atmosphere's carbon. Some marine plants convert dissolved carbon into calcium carbonate, contributing to oceanic carbon storage.
Occurrence of Carbon
The German chemist Wohler synthesised an organic compound (urea) from an inorganic compound (ammonium cyanate). Ever since then, many organic compounds have been made from inorganic compounds. Carbon was found to be the main element in all these compounds. Hence, organic chemistry is also referred to as the chemistry of carbon compounds.
\[\mathrm{NH}_4^+\mathrm{CNO}^-\xrightarrow{\mathrm{Heat}}\mathrm{NH}_2\mathrm{CONH}_2\]
Wohler
The name ‘carbon’ is derived from the Latin word ‘carbo,’ meaning coal. It ranks 17th in terms of abundance in the earth's crust. Carbon is found in nature in free as well as compound states.
Free state: Found as diamond and graphite
Combined state:
- As carbon dioxide and in the form of carbonates such as calcium carbonate, marble, and calamine (ZnCO₃)
- Fossil fuels: coal, petroleum, natural gas
- Carbonaceous nutrients: carbohydrates, proteins, fats
- Natural fibres: cotton, wool, silk
Characteristics of Carbon
1. Catenation Power
- Carbon can form strong covalent bonds with other carbon atoms, creating long chains or ring structures.
- Chains can be open (straight or branched) or closed (cyclic rings). This ability leads to the formation of millions of carbon compounds.
2. Molecular Mass Variation
Carbon compounds range from small molecules (e.g., methane, CH₄) to extremely large ones (e.g., DNA).
Examples of Carbon Compound Molecular Mass:
Carbon Compound | Molecular Mass |
---|---|
Methane (CH₄) (The smallest carbon compound) | 16 |
Cooking gas (C₃H₈ + C₄H₁₀) | 44/58 |
Benzene (C₆H₆) | 78 |
Camphor (C₁₀H₁₆O) | 152 |
Penicillin (C₁₆H₁₈N₂O₄S) | 334 |
Sugar (C₁₂H₂₂O₁₁) | 342 |
Sodium dodecyl benzene sulfonate (a detergent) | 347 |
Fat | ~ 700 |
Starch | ~ 10³ |
Cellulose | ~ 10⁵ |
Protein | ~ 10⁶ |
Polyethylene | ~ 10⁶ |
D.N.A. | ~ 10¹² |
3. Bonding Capability (Tetravalency):
Carbon has four valence electrons and forms covalent bonds with up to four other atoms. It bonds with elements like hydrogen, chlorine, oxygen, nitrogen, sulphur, and phosphorus, creating a vast variety of compounds.
Example: Carbon and chlorine form different compounds based on the number of chlorine atoms attached: CH₄, CH₃Cl, CH₂Cl₂, CHCl₃, CCl₄.
4. Multiple Bond Formation:
Carbon atoms can form single, double, or triple covalent bonds, increasing the diversity of carbon compounds.
Examples:
- Single bond: Ethane (CH₃-CH₃)
- Double bond: Ethene (CH₂=CH₂)
- Triple bond: Ethyne (CH≡CH)
5. Isomerism:
Carbon compounds exhibit isomerism, where molecules with the same molecular formula have different structures and properties. This further increases the number of possible carbon compounds.