Theme: Materials

Unit I: Chemical Substances – Nature and Behaviour

Chemical Reactions

• Chemical Equation: A symbolic representation of a chemical reaction.
• Balanced Chemical Equation: An equation with equal numbers of each type of atom on both sides, reflecting the conservation of mass.
• Implications of a Balanced Chemical Equation: Indicates the proportion of reactants and products, allowing predictions about reaction yields.
• Types of Chemical Reactions:
  • Combination Reaction: Two or more substances combine to form a single product.
  • Decomposition Reaction: A single compound breaks down into two or more simpler substances.
  • Displacement Reaction: An element displaces another in a compound.
  • Double Displacement Reaction: The ions of two compounds exchange places.
  • Precipitation Reaction: A solid forms when two solutions are mixed.
  • Endothermic and Exothermic Reactions: Reactions that absorb or release heat, respectively.
  • Oxidation and Reduction: Oxidation involves the loss of electrons, while reduction involves the gain of electrons.

Acids, Bases, and Salts

• Definitions:
  • Acids: Substances that furnish H⁺ ions in solution.
  • Bases: Substances that furnish OH⁻ ions in solution.
• General Properties and Examples:
  • Acids: Sour taste, turn blue litmus red (e.g., hydrochloric acid).
  • Bases: Bitter taste, slippery feel, turn red litmus blue (e.g., sodium hydroxide).
• Neutralization: The reaction between acids and bases to form water and salt.
• pH Scale: A measure of acidity or alkalinity; important in various biological and chemical processes.
• Preparation and Uses:
  • Sodium Hydroxide: Used in soap making and as a drain cleaner.
  • Bleaching Powder: Used for bleaching and disinfecting.
  • Baking Soda: Used in baking and as an antacid.
  • Washing Soda: Used in glass and soap manufacturing.
  • Plaster of Paris: Used in construction and for making molds.

Metals and Nonmetals

• Properties of Metals and Nonmetals: Metals are typically shiny, malleable, and good conductors; nonmetals are dull, brittle, and poor conductors.
• Reactivity Series: A list of metals arranged by their reactivity.
• Ionic Compounds: Formed by the transfer of electrons from metals to nonmetals.
• Basic Metallurgical Processes: Extraction of metals from ores, refining, and alloying.
• Corrosion and Its Prevention: The deterioration of metals due to environmental reactions; prevention methods include coating and alloying.

Carbon Compounds

• Covalent Bonding: Carbon forms covalent bonds with other elements, leading to a variety of compounds.
• Versatile Nature of Carbon: Can form single, double, and triple bonds, resulting in diverse structures.
• Homologous Series: A series of compounds with the same functional group and similar chemical properties.
• Nomenclature of Carbon Compounds: Includes naming conventions for functional groups (halogens, alcohols, ketones, aldehydes, alkanes, and alkynes).
• Saturated vs. Unsaturated Hydrocarbons: Saturated hydrocarbons contain only single bonds; unsaturated contain double or triple bonds.
• Chemical Properties: Include combustion, oxidation, addition, and substitution reactions.
• Ethanol and Ethanoic Acid: Properties and uses in everyday life; ethanol as a solvent and in beverages; ethanoic acid as vinegar.
• Soaps and Detergents: Used for cleaning; soaps are made from fats and oils, while detergents are synthetic.

Theme: The World of the Living

Unit II: World of Living

Life Processes

• Basic Concepts of Living Beings: Characteristics such as nutrition, respiration, transport, and excretion in both plants and animals.

Control and Coordination

• Tropic Movements in Plants: Growth responses to environmental stimuli (e.g., phototropism, gravitropism).
• Plant Hormones: Chemicals that regulate growth and development (e.g., auxins, gibberellins).
• Control and Coordination in Animals:
  • Nervous System: The system responsible for transmitting signals throughout the body.
  • Voluntary vs. Involuntary Actions: Voluntary actions are controlled consciously, while involuntary actions occur automatically (e.g., reflexes).
  • Chemical Coordination: Involves hormones produced by glands, affecting various body functions.

Reproduction

• Types of Reproduction:
  • Asexual Reproduction: Involves a single parent (e.g., budding, binary fission).
  • Sexual Reproduction: Involves two parents and the fusion of gametes.
• Reproductive Health: Importance of family planning methods and safe sex practices, including awareness of HIV/AIDS.
• Childbearing and Women’s Health: Focus on reproductive health, prenatal care, and maternal health.

Heredity and Evolution

• Heredity: The transmission of traits from parents to offspring.
• Mendel’s Contribution: Established laws of inheritance through experiments with pea plants.
• Sex Determination: Overview of mechanisms that determine the sex of an individual.

Theme: Natural Phenomena

Unit III: Natural Phenomena

Reflection of Light

• Curved Surfaces: How light behaves when reflecting off spherical mirrors.
• Key Terms:
  • Centre of Curvature: The center of the sphere from which the mirror is made.
  • Principal Axis: The line passing through the center of curvature and the mirror’s surface.
  • Principal Focus: The point where parallel rays converge after reflection.
  • Focal Length: The distance between the focus and the mirror.
  • Magnification: The ratio of the height of the image to the height of the object.

Refraction

• Laws of Refraction: Describes how light bends when entering a new medium.
• Refractive Index: A measure of how much light slows down in a medium.

Refraction by Spherical Lenses

• Image Formation: How lenses focus light to form images.
• Lens Formula and Magnification: Used to calculate relationships in lens systems.
• Power of a Lens: The ability of a lens to converge or diverge light.

Functioning of the Human Eye

• Defects of Vision: Common issues such as myopia and hyperopia and their corrections (e.g., glasses, contact lenses).
• Applications of Mirrors and Lenses: In optical devices, cameras, and microscopes.

Refraction of Light through a Prism

• Dispersion of Light: The separation of light into its constituent colors.
• Scattering of Light: How light interacts with particles, leading to phenomena like the blue sky.

Theme: How Things Work

Unit IV: Effects of Current

Electric Current

• Definitions:
  • Electric Current: The flow of electric charge.
  • Potential Difference: The difference in electric potential between two points.
• Ohm’s Law: States that current is directly proportional to voltage and inversely proportional to resistance.

Resistance

• Factors Affecting Resistance: Length, cross-sectional area, and temperature of the conductor.
• Series and Parallel Combinations of Resistors:
  • Series: Resistors connected end-to-end; total resistance increases.
  • Parallel: Resistors connected across the same voltage source; total resistance decreases.

Heating Effect of Electric Current

• Applications: Used in heating appliances like toasters and electric heaters.
• Electric Power: Calculated using the formula P = VI, where P is power, V is voltage, and I is current.

Magnetic Effects of Current

• Magnetic Field and Field Lines: The region around a magnet where magnetic forces are exerted.
• Current-Carrying Conductors: Produce magnetic fields, with the direction given by Fleming’s Left-Hand Rule.
• Direct Current (DC) and Alternating Current (AC): Types of current; AC changes direction periodically.
• Advantages of AC over DC: More efficient for power transmission over long distances.
• Domestic Electric Circuits: Overview of how household wiring systems work.

Theme: Natural Resources

Unit V: Natural Resources

Our Environment

• Ecosystem: A community of living organisms and their physical environment.
• Environmental Problems: Issues such as pollution, deforestation, and climate change.
• Ozone Depletion: The reduction of the ozone layer due to pollutants like CFCs.
• Waste Production: The challenges of managing biodegradable vs. non-biodegradable substances and solutions for waste management.