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 ↓


Metals and Nonmetals


In the study of chemistry, elements are divided into two main categories: metals and nonmetals. Understanding the difference between metals and nonmetals is fundamental to the study of chemistry and understanding how different substances interact and form compounds. In this article, we will explore the properties, characteristics, and examples of metals and nonmetals.

What are metals?

Metals are elements that are generally hard, lustrous, malleable, and good conductors of electricity and heat. Most metals are solid at room temperature, except mercury, which is a liquid. Metals lose electrons in reactions and form positive ions. Metals are shown on the left-hand side of the periodic table.

Properties of metals

Metals have specific physical and chemical properties, based on which they can be identified and classified. These include:

  • Conductivity: Metals are excellent conductors of electricity and heat. This is why materials like copper and aluminum are used in electrical wires.
  • Lustre: Metals are shiny. This is called metallic lustre and is the reason why metals are used in jewellery.
  • Malleability: Metals can be drawn into thin sheets without breaking. For example, gold can be made so thin that it becomes transparent.
  • Ductility: Metals can be stretched into wires. This property is essential for making cables and other flexible electrical connections.
  • Density: Most metals have a high density, which means they are heavy for their size. Osmium and iridium are among the densest metals.
  • High melting and boiling points: Metals generally have high melting and boiling points. For example, tungsten has the highest melting point of any metal.

Chemical properties of metals

  • Reactivity: Metals lose electrons in chemical reactions and form cations, such as sodium (Na) loses an electron to form Na+.
  • Corrosion: Metals like iron corrode when they come in contact with water and oxygen, resulting in corrosion.

Examples of metals

Let's look at some common metals and examples of their uses:

  • Iron (Fe): Used in construction, vehicles, and tools.
  • Aluminum (Al): Light and strong, used in aircraft construction and food packaging.
  • Copper (Cu): Used in electrical wiring and plumbing due to its excellent conductivity.

Visual example: atomic structure of a metal

Metal atoms free electrons

What are nonmetals?

Nonmetals are elements that do not typically have the properties of metals. They are found on the right side of the periodic table. Nonmetals are distinct in being poor conductors of heat and electricity, and they are not ductile or malleable. Instead, they are brittle when solid and most exist as a gas at room temperature.

Properties of non-metals

  • Poor conductors: Non-metals are generally poor conductors of heat and electricity. This is why they are used as insulators.
  • No luster: Nonmetals do not have a metallic luster; instead, they appear dull.
  • Brittle: Solid nonmetals, such as sulfur, break or shatter when hammered.
  • Low Density: Many nonmetals have lower densities than metals.
  • Low melting and boiling points: Non-metals generally have low melting and boiling points. For example, oxygen has a very low boiling point.

Chemical properties of nonmetals

  • Electronegativity: Nonmetals gain electrons to form anions. For example, chlorine gains electrons to form Cl-
  • Reactivity: Nonmetals often form covalent bonds by sharing electrons with other atoms.
  • Oxidizing agents: Nonmetals like oxygen are good oxidizing agents.

Examples of nonmetals

Here are some common nonmetals and their uses:

  • Oxygen (O): Necessary for respiration in most organisms.
  • Carbon (C): Found in all life forms and is a fundamental component of organic chemistry.
  • Nitrogen (N): It makes up 78% of the Earth's atmosphere and is important for protein synthesis in plants and animals.

Visual example: atomic structure of a nonmetal

Nonmetal atoms Shared Electrons

Difference between metals and nonmetals

For a clear understanding, let's compare metals and non-metals:

PropertyMetalsNon-metallic
ConductivityGood conductors of heat and electricityBad conductor
GrowabilityFlexibleBrittle (when solid)
Condition at room temperatureMostly solid (except mercury)Can be solid, liquid, or gas
Electron behaviorTendency to lose electronsTendency to gain or share electrons
AuraShinyMoody

Metalloids

Metalloids or semi-metals have properties that are intermediate between metals and nonmetals. They are found along the zig-zag line separating metals and nonmetals on the periodic table. Examples include silicon and germanium, which are used as semiconductors in electronics.

Properties and examples of metalloids

  • Silicon (Si): Known for its important role in electronics and computer chips.
  • Arsenic (As): Used in some metal alloys and as a doping agent in semiconductors.
  • Semiconductivity: Metalloids can conduct electricity better than nonmetals, but not as well as metals. Their conductivity can be affected by temperature and other conditions.

Visual example: position of metalloids on the periodic table

C Carbon Si Silicon

In summary, understanding the difference between metals, non-metals and metalloids is important in exploring the periodic table and the behavior of different elements in various chemical reactions. These fundamental classifications form the basis for studying more complex chemical processes and applications in various fields of science and industry.


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Metals and Nonmetals

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