Introduction to Metals and Non-Metals

All elements in chemistry are broadly divided into two main categories: metals and non-metals. This classification is based on their physical and chemical properties.

Metals are generally electropositive elements that tend to lose electrons and form positive ions, while non-metals are electronegative elements that tend to gain electrons and form negative ions.

This chapter is very important for understanding chemical reactions, bonding, and industrial uses of elements.

• Metals → Lose electrons → Form cations
• Non-metals → Gain electrons → Form anions
• Important for daily life and industries

Metals

Metals are the elements that conduct heat and electricity and are malleable and ductile in nature. They are electropositive elements because they lose electrons easily.

Metals are found in the Earth's crust mainly in the form of ores. They are extracted and purified for various industrial uses.

Examples of Metals

• Iron (Fe)
• Copper (Cu)
• Aluminium (Al)
• Gold (Au)
• Silver (Ag)
• Zinc (Zn)
• Sodium (Na)
• Potassium (K)
• Calcium (Ca)
• Magnesium (Mg)

Formation of Ions

Metals lose electrons to form positive ions.

This property is called electropositivity.

General Characteristics of Metals

• Metals are electropositive in nature.
• They lose electrons easily.
• They form ionic bonds with non-metals.
• They have metallic bonding.
• They are generally solid at room temperature.
• They have high melting and boiling points.
• They are strong and durable.

Physical Properties of Metals

1. Hardness

Most metals are hard substances. However, some metals like sodium and potassium are soft and can be cut with a knife.

2. Strength

Metals have high tensile strength, which means they can withstand heavy loads without breaking.

3. State

Metals are generally solid at room temperature. Exception: Mercury is a liquid metal.

4. Sonorous Nature

Metals produce a ringing sound when struck. This property is called sonority.

5. Conductivity

Metals are good conductors of heat and electricity.

• Copper is used in electrical wires.
• Aluminium is used in power transmission lines.

6. Malleability

Metals can be beaten into thin sheets.

• Gold is the most malleable metal.
• Used in making foils and sheets.

7. Ductility

Metals can be drawn into thin wires.

• Copper wires are used in electricity.

8. Melting and Boiling Point

Metals generally have high melting and boiling points.

• Exception: Sodium and potassium have low melting points.

9. Density

Most metals have high density and are heavy.

10. Colour

Most metals are grey in colour.

• Gold is yellow
• Copper is reddish-brown

Uses of Metals

Metals are very important in daily life and industries.

• Iron is used in construction of buildings and bridges.
• Copper is used in electrical wiring.
• Aluminium is used in utensils and aircraft.
• Gold and silver are used in jewellery.
• Zinc is used in galvanization.

Modern life is not possible without metals because they are used in machines, vehicles and technology.

Non-Metals

Non-metals are elements that do not have metallic properties. They are generally electronegative in nature and tend to gain electrons during chemical reactions.

Non-metals are found on the right side of the periodic table. They exist in different physical states such as solid, liquid and gas.

Examples of Non-Metals

• Oxygen (O)
• Nitrogen (N)
• Carbon (C)
• Sulfur (S)
• Chlorine (Cl)
• Bromine (Br)
• Phosphorus (P)
• Hydrogen (H)

Formation of Ions

Non-metals gain electrons to form negative ions (anions).

This property is known as electronegativity.

General Characteristics of Non-Metals

• Non-metals are electronegative in nature.
• They gain electrons easily.
• They form covalent bonds with other non-metals.
• They are generally poor conductors of heat and electricity.
• They have low melting and boiling points.
• They are not malleable or ductile.
• They are usually soft and brittle.

Physical Properties of Non-Metals

1. State

Non-metals exist in all three states:

• Solid → Carbon, Sulfur
• Liquid → Bromine
• Gas → Oxygen, Nitrogen

2. Lustre

Non-metals are generally dull in appearance.

• Exception: Iodine has a shiny surface.

3. Hardness

Non-metals are generally soft.

• Exception: Diamond is the hardest natural substance.

4. Malleability

Non-metals are not malleable and cannot be beaten into sheets.

5. Ductility

Non-metals are not ductile and cannot be drawn into wires.

6. Conductivity

Non-metals are poor conductors of electricity.

• Exception: Graphite conducts electricity.

7. Sonorous Nature

Non-metals do not produce sound when struck.

8. Melting and Boiling Point

Non-metals have low melting and boiling points.

9. Density

Non-metals generally have low density.

Uses of Non-Metals

Non-metals are very important for life and industries.

• Oxygen is essential for respiration.
• Nitrogen is used in fertilizers.
• Carbon is used as fuel.
• Chlorine is used in water purification.
• Phosphorus is used in matchsticks.

Non-metals are important for biological processes and environmental balance.

Difference Between Metals and Non-Metals

Important Concepts (Advanced Theory)

The difference between metals and non-metals is very important in chemistry. It helps in understanding bonding and reactions.

Metals generally form ionic compounds by transferring electrons, while non-metals form covalent compounds by sharing electrons.

Some elements show both metallic and non-metallic properties and are called metalloids.

• Examples: Silicon, Germanium

Understanding these concepts is essential for exams and real-life applications.

Chemical Properties of Metals

Chemical properties describe how metals react with different substances such as oxygen, water, acids and other compounds. These reactions are very important for understanding the reactivity and uses of metals.

1. Reaction of Metals with Oxygen

Metals react with oxygen to form metal oxides.

Examples

Nature of Metal Oxides

• Most metal oxides are basic in nature.
• They turn red litmus blue.

Amphoteric Oxides

Some metal oxides react with both acids and bases.

• Examples: Aluminium oxide (Al₂O₃), Zinc oxide (ZnO)

Gold and silver do not react with oxygen easily because they are least reactive metals.

2. Reaction of Metals with Water

Metals react with water to produce metal hydroxide and hydrogen gas.

Examples

Some metals react with steam instead of cold water:

Important Points

• Highly reactive metals react violently with water.
• Sodium and potassium are stored in kerosene to prevent reaction with air and water.
• Less reactive metals do not react with water.

3. Reaction of Metals with Acids

Metals react with dilute acids to form salt and hydrogen gas.

Examples

Important Points

• Hydrogen gas is evolved.
• More reactive metals react faster.
• Less reactive metals react slowly.

Special Case: Nitric Acid

Nitric acid (HNO₃) is a strong oxidising agent. It does not produce hydrogen gas with metals.

4. Displacement Reaction

A more reactive metal displaces a less reactive metal from its compound.

Examples

Explanation

Iron is more reactive than copper, so it displaces copper from copper sulfate solution.

• This reaction depends on the reactivity series.
• Used in extraction and purification of metals.

5. Metal Oxides

Metal oxides are generally basic in nature and react with acids to form salt and water.

Some metal oxides are amphoteric and react with both acids and bases.

Corrosion (Introduction)

Corrosion is the gradual destruction of metals due to reaction with air, moisture or other environmental factors.

The most common example is rusting of iron.

Corrosion weakens metals and reduces their life.

Chemical Properties of Non-Metals

Non-metals are generally electronegative elements that gain electrons during chemical reactions. Their chemical behavior is different from metals.

1. Reaction of Non-Metals with Oxygen

Non-metals react with oxygen to form non-metal oxides.

Examples

Nature of Non-Metal Oxides

• Non-metal oxides are acidic in nature.
• They turn blue litmus red.

Reaction with Water

Non-metal oxides dissolve in water to form acids.

2. Reaction of Non-Metals with Hydrogen

Non-metals react with hydrogen to form covalent compounds.

Examples

3. Reaction of Non-Metals with Metals

Non-metals react with metals to form ionic compounds.

In these reactions, metals lose electrons and non-metals gain electrons.

Ionic Compounds

Ionic compounds are formed by the transfer of electrons from metals to non-metals. This results in the formation of positively charged and negatively charged ions.

Formation of Ionic Bond

The force of attraction between oppositely charged ions is called electrostatic force. This force holds the ions together in an ionic compound.

Properties of Ionic Compounds

1. Physical Nature

• Ionic compounds are solid and crystalline.
• They are hard but brittle.

2. Melting and Boiling Point

• Ionic compounds have high melting and boiling points.
• This is due to strong electrostatic forces.

3. Solubility

• Most ionic compounds are soluble in water.
• They are insoluble in organic solvents.

4. Electrical Conductivity

• Ionic compounds conduct electricity in molten state.
• They do not conduct electricity in solid state.

Difference Between Ionic and Covalent Compounds

Important Concepts (Advanced)

The formation of ionic compounds depends on the difference in electronegativity between elements. Greater the difference, stronger the ionic bond.

Non-metals are important in biological systems. For example:

• Oxygen is used in respiration.
• Carbon is the basis of life.
• Nitrogen is essential for proteins.

Understanding ionic bonding helps in understanding chemical reactions and properties of compounds.

Reactivity Series of Metals

Reactivity series is the arrangement of metals in decreasing order of their reactivity. It helps in predicting the chemical behavior of metals.

Explanation

• Metals at the top are highly reactive.
• Metals at the bottom are least reactive.
• Highly reactive metals react quickly with water and acids.
• Least reactive metals do not react easily.

Importance of Reactivity Series

• Helps in displacement reactions.
• Helps in extraction of metals.
• Helps in understanding corrosion.

Displacement Example

Zinc is more reactive than copper, so it displaces copper from its compound.

Extraction of Metals

Metals are extracted from their ores using different methods depending on their reactivity.

Steps of Extraction

• 1. Concentration of Ore
• 2. Roasting or Calcination
• 3. Reduction

1. Concentration of Ore

Removal of impurities like soil and sand from ore.

2. Roasting

Heating of ore in presence of oxygen.

3. Calcination

Heating of ore in absence of air.

4. Reduction

Conversion of metal oxide into metal.

Based on Reactivity

• Highly reactive → Electrolysis (Na, K)
• Moderately reactive → Reduction with carbon (Fe, Zn)
• Low reactive → Heating (Cu, Hg)

Important Concepts (Extraction)

Highly reactive metals cannot be extracted using carbon because they are very reactive. Therefore, electrolysis is used.

Moderately reactive metals are extracted by reducing their oxides using carbon.

Low reactive metals are found in native state or extracted by simple heating.

Corrosion

Corrosion is the gradual destruction of metals due to reaction with air, moisture or chemicals.

Example: Rusting of Iron

Rust is a reddish-brown substance formed on iron.

Conditions for Rusting

• Presence of oxygen
• Presence of water

Effects of Corrosion

• Weakens metals
• Reduces life of structures
• Causes economic loss

Prevention of Corrosion

• Painting
• Oiling and greasing
• Galvanization (zinc coating)
• Alloying

These methods prevent contact of metal with air and moisture.

Alloys

Alloys are homogeneous mixtures of two or more metals or a metal and a non-metal.

Purpose of Alloys

• Increase strength
• Improve hardness
• Prevent corrosion

Examples

• Brass = Copper + Zinc
• Bronze = Copper + Tin
• Steel = Iron + Carbon
• Stainless Steel = Iron + Chromium + Nickel

Quick Revision (Exam Booster)

• Metals → Lose electrons → Cations
• Non-metals → Gain electrons → Anions
• Ionic bond → Transfer of electrons
• Reactivity series → Important for reactions
• Corrosion → Rusting of iron
• Alloys → Improve properties

Additional Important Points

Metals and non-metals play a very important role in our daily life. Understanding their properties helps us use them effectively.

This chapter is important for exams as well as real-life applications.

Focus on reactions, properties and concepts for better understanding.

All Important Equations of Metals and Non-Metals

This section contains all important chemical equations of the chapter for quick revision.

1. Reaction of Metals with Oxygen

2. Reaction of Metals with Water

3. Reaction of Metals with Acids

4. Displacement Reactions

5. Metal Oxides

6. Amphoteric Oxides

7. Reaction of Non-Metals

8. Non-Metal Oxide with Water

9. Reaction with Hydrogen

10. Formation of Ionic Compounds

11. Extraction of Metals

12. Corrosion (Rusting)

Final Equation Summary

• Metal + Oxygen → Metal Oxide
• Metal + Water → Metal Hydroxide + Hydrogen
• Metal + Acid → Salt + Hydrogen
• Non-metal + Oxygen → Acidic Oxide
• Ionic Bond → Transfer of electrons