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 ↓


Chemical properties


Chemical properties are characteristics of a substance that become apparent when it undergoes a chemical change or reaction. These properties can only be observed during a chemical reaction, as one substance changes into another substance with a new chemical structure. Understanding chemical properties helps us predict how substances will behave in different situations, and is essential in fields such as chemistry, biology, engineering, and environmental science.

Examples of chemical properties

Some common examples of chemical properties include reactivity, flammability, acidity or alkalinity, and oxidation state. Let's look at each of these in detail.

Reactivity

Reactivity is the ability of a substance to react chemically with other substances. For example, sodium is a highly reactive metal, especially with water:

    2 Na + 2 H2O → 2 NaOH + H2 ↑

This equation shows that when sodium (Na) reacts with water (H2O), it forms sodium hydroxide (NaOH) and hydrogen gas (H2).

Sodium (Na) Water (H2O) NaOH H2 Gas

Flammability

Flammability is the ability of a substance to burn in the presence of oxygen. For example, when wood burns, it combines with oxygen in a chemical reaction to form carbon dioxide, water vapor, ash, and release heat.

    C6H10O5 + 6 O2 → 6 CO2 + 5 H2O + heat

In this case, the cellulose in wood (C6H10O5) reacts with oxygen (O2) to produce carbon dioxide (CO2), water (H2O) and heat, which is what we feel when we burn.

Acidity and alkalinity

The acidity or alkalinity of a substance is measured on the pH scale, which ranges from 0 to 14. Substances that have a pH less than 7 are considered acidic, while those with a pH greater than 7 are considered basic (or alkaline).

For example, hydrochloric acid (HCl) is a strong acid:

    HCl → H+ + Cl-

Sodium hydroxide (NaOH) is a strong base:

    NaOH → Na+ + OH-
0 7 14 Acidic Basic

Oxidation state

The oxidation state, or oxidation number, shows the degree of oxidation (loss of electrons) of an atom in a chemical compound. For example, in water (H2O), the oxidation state of hydrogen is +1, and that of oxygen is -2:

    2H+ + O2- → H2O

Why are chemical properties important?

Chemical properties are important because they help scientists and students understand how substances interact with one another. This understanding is vital for developing new materials, medicines, fuels, and practically everything we use every day. Knowing chemical properties helps us identify substances and predict how they will react, which is useful in laboratory experiments, industrial processes, and everyday life decisions such as choosing cleaning products or medications.

Real-world applications of chemical properties

By understanding chemical properties, we can apply this knowledge in a variety of areas:

Medicine

In medicine, chemical properties are essential for creating drugs that interact with the body in specific ways. For example, the acidity or alkalinity of a drug can affect its absorption and effectiveness in the body.

Environmental science

Chemical properties are fundamental in understanding environmental issues, such as acid rain caused by emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) into the atmosphere:

    SO2 + H2O → H2SO3 (Sulfurous acid)

Understanding these reactions helps in formulating strategies for pollution control and environmental protection.

Food chemistry

Chemical properties are important in food chemistry to keep food safe and understand its nutritional properties. For example, oxidation reactions can cause food to spoil, so antioxidants such as vitamin C are added to maintain freshness.

Conclusion

Chemical properties provide an important basis for understanding the interactions between substances. They can only be observed during chemical reactions and are essential for progress in science and industry. By analyzing these properties, we can better understand both the natural world and the manufactured materials we use in our daily lives.


Grade 7 → 2.3.2


U
username
0%
completed in Grade 7

← Prev (2.3.1)
Physical properties
Next (2.4) →
States of matter

Comments 



Chemical properties

https://www.chemistryelite.com/g7/2.3.2?ceal=en