Grade 9
  1. Matter and its nature  1.1. Introduction to matter  1.2. Physical and chemical properties of matter  1.3. States of matter  1.3.1. Solid state  1.3.2. Fluid state  1.3.3. Gaseous state  1.3.4. Plasma and Bose–Einstein condensate  1.4. Changes in the states of matter  1.4.1. Melting and freezing  1.4.2. Evaporation and Condensation  1.4.3. Sublimation and deposition  1.5. Classification of matter  1.6. Elements, Compounds, and Mixtures  1.7. Pure substances and impurities  1.8. Separation Techniques  1.8.1. Filtration  1.8.2. Distillation  1.8.3. Crystallization  1.8.4. Chromatography  1.8.5. Centrifugation  1.8.6. Sublimation  1.8.7. Decantation and sedimentation
  2. Atomic Structure  2.1. Discovery of atoms  2.2. Dalton's atomic theory  2.3. Structure of the atom  2.4. Subatomic particles  2.5. Atomic number and mass number  2.6. Isotopes and Isobars  2.7. Electronic configuration  2.8. Bohr's atomic model  2.9. Modern Atomic Model (Quantum Mechanical Model - Introduction)  2.10. Valency and chemical bonding
  3. C hemical reactions and equations  3.1. Introduction to Chemical Reactions  3.2. Chemical Equation Formulation  3.3. Balancing Chemical Equations  3.4. Types of Chemical Reactions  3.4.1. Combination Reactions  3.4.2. Decomposition reactions  3.4.3. Displacement reactions  3.4.4. Double displacement reactions  3.4.5. Redox reactions  3.4.6. Endothermic and Exothermic Reactions  3.5. Effects of chemical reactions  3.6. Energy Changes in Chemical Reactions  3.7. Catalysts and their role in reactions
  4. Periodic table and periodicity  4.1. History of Periodic Classification  4.2. Mendeleev's periodic table  4.3. Modern Periodic Table  4.4. Periods and groups in the periodic table and periodicity  4.5. Trends in the Periodic Table  4.5.1. Atomic size  4.5.2. Ionization Energy  4.5.3. Electron affinity  4.5.4. Electronegativity  4.5.5. Metallic and Non-Metallic Properties  4.6. Noble gases and their properties
  5. Chemical bond  5.1. Introduction to Chemical Bonding  5.2. Types of chemical bonds  5.2.1. Ionic bond  5.2.2. Covalent bond  5.2.3. Metallic bond  5.2.4. Hydrogen bonding  5.2.5. Van der Waals force  5.3. Properties of Ionic and Covalent Compounds  5.4. Molecular Structure and Geometry (VSEPR Theory - Basics)
  6. Acids, Bases and Salts  6.1. Introduction to Acids and Bases  6.2. Properties of Acids  6.3. Properties of bases  6.4. pH scale and its importance  6.5. Indicators and their uses  6.6. Neutralization reactions  6.7. Strength of Acids and Bases (Strong vs. Weak)  6.8. Preparation of salts  6.9. Uses of acids, bases and salts in daily life
  7. Metals and Nonmetals  7.1. Physical Properties of Metals  7.2. Physical Properties of Nonmetals  7.3. Chemical properties of metals  7.4. Chemical Properties of Nonmetals  7.5. Reactivity Series of Metals  7.6. Extraction of metals  7.7. Corrosion and its prevention  7.8. uses of metals and nonmetals
  8. Carbon and its compounds  8.1. Introduction to Carbon  8.2. Allotropes of carbon (diamond, graphite, fullerene)  8.3. Hydrocarbons  8.3.1. Hydrocarbons  8.3.2. Alkene  8.3.3. Alkynes  8.4. Functional groups in organic chemistry  8.5. Isomerism in organic compounds  8.6. Alcohols and Carboxylic Acids  8.7. Soaps and detergents  8.8. Polymers (Introduction to Natural and Synthetic Polymers)
  9. Solutions and Mixtures  9.1. Types of mixtures  9.2. Homogeneous and Heterogeneous Mixtures  9.3. Concentration of solutions  9.4. Solubility and factors affecting solubility  9.5. Suspensions and Colloids  9.6. Saturated, unsaturated and supersaturated solutions
  10. Air and atmosphere  10.1. Composition of air  10.2. Role of gases in the atmosphere  10.4. Acid rain and its effects  10.5. Greenhouse effect and global warming  10.6. Ozone layer and its depletion  10.7. Air pollution control measures
  11. Water and its importance  11.1. Composition and properties of water  11.2. Hardness of water (temporary and permanent hardness)  11.3. Causes of water pollution  11.4. Effects of Water Pollution  11.5. Water purification methods (filtration, boiling, chlorination)
  12. Industrial Chemistry  12.1. Introduction to Industrial Chemistry  12.2. Important industrial chemicals (sulfuric acid, ammonia, sodium hydroxide)  12.3. Chemical processes in industry  12.4. Uses of Industrial Chemistry in Daily Life  12.5. Environmental impact of industrial chemical processes

Grade 9 ↓


Matter and its nature


Matter is a fundamental concept in chemistry and science in general. It refers to anything that occupies space and has mass. Matter exists all around us and makes up everything we see, touch, and interact with in our daily lives.

Definition of matter

Basically, matter is defined as anything that has mass and occupies space. Mass is a measure of the amount of matter in an object, and it is usually measured in grams or kilograms. The space occupied by matter is called volume.

For example, a wooden table, the air we breathe, the water we drink and the clothes we wear are all examples of matter. They all take up space and have mass.

States of matter

Matter exists in various forms, also called states. The most common known states of matter are solid, liquid, and gas. However, there are other states such as plasma and Bose-Einstein condensate. Let's explore the three primary states.

Solid state

Matter in the solid state has a definite shape and volume. The particles in a solid are closely packed with each other in a definite arrangement due to which solids retain their shape and are incompressible.

        Examples: ice
        The water molecules in ice are arranged in a crystalline structure, where they can only vibrate in certain positions.

Fluid state

Liquids have a definite volume, but they do not have a definite shape. Instead, they take the shape of whatever container they are kept in. The particles in a liquid are not as tightly packed together as in a solid, so they can move freely and slide over one another.

        Examples: water
        When you pour water into a glass, it takes the shape of the glass but its volume remains intact.

Gas state

Matter in the gaseous state has neither a definite shape nor a definite volume. Gases expand to fill the entire space available to them, which means they can be easily compressed. The particles in a gas move quickly and are farther apart than in solids and liquids.

        Examples: oxygen
        Oxygen gas fills any vessel, and gets distributed evenly throughout the vessel.

Properties of matter

Understanding the properties of matter is important for identifying and distinguishing different types of matter. The properties of matter are classified into physical properties and chemical properties.

Physical properties

Physical properties are characteristics of matter that can be seen or measured without changing the substance's composition. Physical properties include color, odor, density, boiling point, and melting point.

        Example: Boiling point of water
        The boiling point of water is 100°C (212°F) at standard atmospheric pressure.

Chemical properties

Chemical properties describe a substance's ability to undergo a chemical change or reaction. The chemical properties of a substance can only be observed during a chemical reaction, which changes the identity of the substance.

        Example: Rusting of iron
        Iron reacts with oxygen in the presence of water to form rust, which shows its chemical property of susceptibility to oxidation.
4Fe + 3O 2 + 6H 2 O → 4Fe(OH) 3

Composition of matter

Matter is made up of atoms and molecules. Atoms are the basic units of matter and they combine in different ways to form molecules. Atoms themselves are made up of subatomic particles: protons, neutrons, and electrons.

Atoms

An atom consists of a nucleus containing protons and neutrons, surrounded by electrons orbiting the nucleus. An atom is the smallest unit of an element that retains the properties of that element.

        Example: hydrogen atom
        A hydrogen atom has one proton and one electron.

Molecules

Molecules are formed when two or more atoms chemically bond together. Molecules can be elements or compounds. Elements are pure substances made up of only one type of atom, while compounds are made up of two or more different atoms.

        Example: water molecule
        Water is a compound consisting of two hydrogen atoms bonded to one oxygen atom.
H 2 O

Differentiating between elements, compounds, and mixtures

To understand matter it is important to distinguish between elements, compounds and mixtures.

Elements

Elements are pure substances that contain only one type of atom. They cannot be broken down into simpler substances by chemical means. The periodic table organizes elements based on their properties.

        Example: gold (Au)
        Gold is an element that consists of only gold atoms.

Compounds

Compounds are pure substances made from two or more different elements that are chemically combined in a definite ratio. The properties of compounds differ from those of the individual elements they are made of.

        Example: Sodium chloride (NaCl)
        Table salt is composed of sodium (Na) and chlorine (Cl) atoms.

Mixture

A mixture is a combination of two or more substances where each substance retains its own properties and can be physically separated. Mixtures can be homogeneous or heterogeneous.

Homogeneous mixture

Homogeneous mixtures, also known as solutions, have a uniform composition throughout.

        Examples: salt water
        Salt dissolved in water forms a homogeneous mixture.

Heterogeneous mixtures

Heterogeneous mixtures have an uneven structure, where different parts can be seen.

        Example: Sand and iron filings
        By mixing sand with iron filings, a heterogeneous mixture is obtained.

Changes in matter

Physical and chemical changes can occur in matter. Understanding these changes helps us understand how substances interact and transform.

Physical changes

Physical changes are changes in the physical form or properties of a substance, but without any change in its chemical composition. Examples include melting, freezing, and breaking down.

        Example: Melting ice
        When ice melts it changes from a solid to a liquid, but it remains H2O.

Chemical changes

A chemical change results in the formation of new substances with different properties from the original substances. Indicators of a chemical change include color changes, temperature changes, gas production, and precipitate formation.

        Examples: burning wood
        Burning wood produces ash, carbon dioxide and water, which represents a chemical change.

Observing changes in matter

To further understand the transformations between different states of matter, consider the phase changes that occur:

  • solid to liquid: melting
  • Liquid to Solid: Freezing
  • Liquid to Gas: Evaporation
  • Gas to Liquid: Condensation
  • Solid to Gas: Sublimation
  • Gas to Solid: Deposition

These phase changes represent physical transitions of matter:

Solid liquid Gas melting Evaporation Evaporation solidify

Conclusion

The study of matter and its nature provides insight into the building blocks of the universe. By understanding the properties, structure, and transformations of matter, we can better understand the physical world and its various phenomena. Knowledge of matter not only aids scientific exploration but is also vital for real-world applications ranging from industrial processes to environmental science.


Grade 9 → 1


U
username
0%
completed in Grade 9

Next (1.1) →
Introduction to matter

Comments 



Matter and its nature

https://www.chemistryelite.com/g9/1?ceal=en