Grade 7
  1. Introduction to Chemistry  1.1. What is Chemistry?  1.2. Importance of chemistry in daily life  1.3. Branches of chemistry  1.4. Scientific Method in Chemistry  1.5. Laboratory Safety Rules and Precautions  1.6. Common Laboratory Equipment and Their Uses  1.7. Units of measurement in chemistry
  2. Matter and its properties  2.1. Definition of Matter  2.2. Classification of matter  2.3. Properties of matter  2.3.1. Physical properties  2.3.2. Chemical properties  2.4. States of matter  2.4.1. Solid state  2.4.2. Fluid state  2.4.3. Gaseous state  2.4.4. Plasma and Bose–Einstein condensates  2.5. Changes in the states of matter  2.5.1. Melting and freezing  2.5.2. Evaporation and Condensation  2.5.3. Sublimation and deposition  2.6. Density and its applications  2.7. Diffusion and its importance
  3. Elements, Compounds, and Mixtures  3.1. Definition of the element  3.2. Classification of elements  3.3. Metals, Nonmetals and Metalloids  3.4. Noble gases and their properties  3.5. Introduction to the Periodic Table  3.6. Definition of Compound  3.7. Properties of Compounds  3.8. Introduction to Chemical Formulas  3.9. Definition of Mixture  3.10. Types of mixtures  3.10.1. Homogeneous mixture  3.10.2. Heterogeneous mixtures  3.11. Difference Between Compounds and Mixtures  3.12. Solutions, Colloids and Suspensions
  4. Separation of mixtures  4.1. Need for separation of mixtures  4.2. Separation methods  4.2.1. Filtration  4.2.2. Sedimentation and decantation  4.2.3. Evaporation  4.2.4. Crystallization  4.2.5. Distillation  4.2.6. Chromatography  4.2.7. Magnetic Separation  4.2.8. Centrifugation
  5. Atomic Structure  5.1. Introduction to Atoms  5.2. Structure of the atom  5.2.1. Nucleus and electron cloud  5.3. Subatomic particles  5.3.1. Proton  5.3.2. Neutron  5.3.3. Electrons  5.4. Atomic number and mass number  5.5. Isotopes and their uses  5.6. Ions and ion formation
  6. Periodic table  6.1. Introduction to the Periodic Table  6.2. Groups and periods  6.3. Trends in the Periodic Table  6.3.1. Atomic Size  6.3.2. Metallic and non-metallic character  6.3.3. Electronegativity  6.3.4. Reactivity of the elements  6.4. Alkali metals and their properties
  7. Chemical bond  7.1. Why do atoms form bonds?  7.2. Types of chemical bonds  7.2.1. Ionic bond  7.2.2. Covalent bond  7.2.3. Metal Bond  7.3. Properties of Ionic and Covalent Compounds  7.4. Intermolecular forces
  8. Chemical reactions  8.1. Introduction to Chemical Reactions  8.2. Signs of a chemical reaction  8.3. Types of Chemical Reactions  8.3.1. Combination Reactions  8.3.2. Decomposition reactions  8.3.3. Displacement reactions  8.3.4. Double displacement reactions  8.3.5. Combustion reactions  8.4. Law of conservation of mass  8.5. Balancing simple chemical equations
  9. Acids, Bases and Salts  9.1. Definition of Acid and Base  9.2. Properties of Acids  9.3. Properties of bases  9.4. pH Scale and Indicators  9.5. Neutralization reactions  9.6. Common Acids and Bases in Everyday Life  9.7. Preparation and use of salts  9.8. Strong and weak acids and bases
  10. Solutions and Solubility  10.1. Definition of Solution  10.2. Components of the solution  10.2.1. Solvent  10.2.2. solute  10.3. Factors Affecting Solubility  10.4. Concentration of solutions  10.5. Saturated and unsaturated solutions  10.6. Colloids and suspensions  10.7. Solubility curve and its interpretation
  11. Air and atmosphere  11.1. Composition of air  11.2. Properties of gases in the air  11.3. Importance of Oxygen and Carbon Dioxide  11.4. Air pollution and its effects  11.5. Greenhouse effect and global warming  11.6. Ways to reduce air pollution  11.7. Ozone layer and its importance
  12. Water and its importance  12.1. Properties of Water  12.2. Water as the universal solvent  12.3. Importance of water for life  12.4. Water pollution and its effects  12.5. Water Purification  12.5.1. Filtration  12.5.2. boil  12.5.3. Chlorination in water purification  12.5.4. reverse osmosis  12.6. Hard and soft water  12.7. Water cycle and its importance
  13. Fuel and energy  13.1. Types of fuel  13.1.1. Fossil fuels  13.1.2. Renewable energy sources  13.2. Combustion and energy release  13.3. Global warming and its effects  13.4. Alternative sources of energy  13.5. Ways to conserve energy
  14. Metals and Nonmetals  14.1. Physical and chemical properties of metals  14.2. Physical and Chemical Properties of Non-Metals  14.3. Difference Between Metals and Nonmetals  14.4. Uses of metals and nonmetals  14.5. Corrosion of metals and its prevention  14.6. Alloys and their importance
  15. Plastics and polymers  15.1. Natural and synthetic polymers  15.2. Properties of plastics  15.3. Biodegradable and Non-Biodegradable Plastics  15.4. Environmental impact of plastic  15.5. Recycling and waste management in plastics and polymers  15.6. Daily Uses of Polymers
  16. Introduction to Organic Chemistry  16.1. Basic definitions of organic chemistry  16.2. Carbon Compounds in Daily Life  16.3. Hydrocarbons  16.4. Simple functional groups (alcohols and carboxylic acids)  16.5. Importance of organic compounds in industry

Grade 7 → Matter and its properties ↓


Properties of matter


Matter is everything that has mass and occupies space. It is composed of atoms and molecules and makes up everything in the universe, including us. In chemistry, understanding the properties of matter is fundamental. These properties determine how matter behaves under different conditions and with other substances.

1. Introduction to matter

Matter exists in different states commonly known as solid, liquid and gas. Each state has its own properties:

  • Solid: It has definite shape and volume. The particles are very closely packed to each other and arranged in a definite position.
  • Liquid: It has a definite volume but no definite shape; it conforms to the shape of its container. The particles are close to each other but can move freely.
  • Gas: It has no definite shape or volume. Gas particles are spread out and move around freely.

Visual example: States of matter

Rectangle represents solid, circle represents liquid, and ellipse represents gas, which shows their shapes.

2. Physical properties of matter

Physical properties are characteristics that can be seen or measured without any change in matter. These include:

  • Colour: The appearance or color of a substance.
  • Odor: The odor emitted by a substance.
  • Melting point: The temperature at which a solid becomes a liquid.
  • Boiling point: The temperature at which a liquid changes into a gas.
  • Density: The mass per unit volume of a substance.
    • Density = mass / volume
  • Solubility: The ability of a substance to dissolve in a solvent.
  • Conductivity: The ability of a material to conduct electricity or heat.

Example: Density calculation

Consider a piece of metal weighing 200 grams and having a volume of 50 cubic centimeters. Its density is calculated as follows:

Density = 200 g / 50 cm3 = 4 g/cm3

3. Chemical properties of the substance

Chemical properties describe how a substance reacts with other substances and changes its structure. These include:

  • Reactivity: How a substance reacts with other substances, including acids, bases, and water.
  • Flammability: The ability of a substance to burn or ignite.
  • Oxidation states: The ability of an atom to lose or gain electrons during a chemical reaction.

Example: Reactivity with water

Consider the reaction of sodium with water:

2Na + 2H2O → 2NaOH + H2

This shows the reactivity of sodium with water, producing sodium hydroxide and hydrogen gas.

4. Intensive vs. extensive properties

Properties of matter may also be classified as intensive or extensive:

  • Intensive properties: do not depend on the amount of matter present. Examples include density, boiling point, and color.
  • Extensive properties: depend on the amount of matter present. Examples include mass, volume, and length.

Visual example: Intensive vs. extensive properties

Mass Volume Colour

This line graph shows properties located along a line representing a spectrum from extensive to intensive properties.

5. Observation of the properties of matter

Scientists observe the properties of matter using a variety of methods and instruments. Observations are often made with the senses or special instruments. For example:

  • Microscope: Used to view microscopic structures in solids.
  • Thermometer: Used to measure melting point and boiling point.
  • Balancers: Used to measure mass.

Example: Using a thermometer

To find the boiling point of water, a thermometer is placed in the water and heated until it starts to boil:

Boiling point as observed on thermometer at standard atmospheric pressure = 100°C.

6. Applications and significance in the real world

Understanding the properties of matter is important in everyday life and industrial applications. For example:

  • Cooking: Knowing the boiling point of water helps in cooking.
  • Construction: The density and strength of the materials are considered to ensure safety and durability.
  • Chemical manufacturing: Reactivity and solubility information guides safe and efficient production.

In conclusion, the properties of matter are essential for understanding the physical and chemical characteristics of the world around us. Whether in laboratories or in everyday life, recognizing and applying these properties leads to a deeper understanding of the universe.


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Properties of matter

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