What is Metals and Non-metals Class 10: Complete NCERT Guide

Definition and Classification of Metals and Non-metals

In Class 10 Science, NCERT defines metals as elements that are generally hard, shiny, malleable, ductile, and good conductors of heat and electricity. They tend to lose electrons to form positive ions (cations).

Non-metals, on the other hand, are elements that are usually soft or brittle, lack luster, and are poor conductors of heat and electricity. They tend to gain electrons to form negative ions (anions).

Classification:

• Metals: Examples include iron, copper, aluminium, zinc.
• Non-metals: Examples include sulfur, oxygen, carbon, chlorine.

This classification helps students understand their distinct physical and chemical properties.

Physical Properties of Metals and Non-metals

Understanding the physical properties is crucial for identifying metals and non-metals:

These properties are tested in experiments and help in practical identification.

Chemical Properties and Reactivity Trends

Chemically, metals and non-metals behave differently:

• Metals tend to lose electrons and form positive ions. For example, sodium (Na) loses one electron to form Na⁺.
• Non-metals tend to gain electrons to form negative ions. For example, chlorine (Cl) gains one electron to form Cl⁻.

Reaction with Oxygen:

• Metals form basic oxides (e.g., $2Mg + O_2 \rightarrow 2MgO$).
• Non-metals form acidic oxides (e.g., $C + O_2 \rightarrow CO_2$).

Reaction with Water:

• Some metals react with water to release hydrogen gas (e.g., $2Na + 2H_2O \rightarrow 2NaOH + H_2$).
• Non-metals generally do not react with water.

These reactions illustrate their chemical nature and help in distinguishing them.

Uses of Metals and Non-metals in Daily Life

Metals and non-metals have important applications based on their properties:

• Metals:
• Iron is used in construction and manufacturing.
• Copper is used in electrical wiring due to its conductivity.
• Aluminium is used in aircraft and kitchen utensils.

• Non-metals:
• Oxygen is essential for respiration.
• Sulfur is used in making matches and fertilizers.
• Carbon is the basis of all life and used in pencils (graphite).

Knowing these uses helps students relate theory to real-world applications.

Comparison Table: Metals vs Non-metals

Here is a quick comparison to summarise key differences:

This table is useful for quick revision before exams.

Worked Example: Identifying Metals and Non-metals

Example: Classify the following elements as metals or non-metals based on their properties:

• Sodium (Na): Shiny, reacts with water to produce hydrogen.
• Sulfur (S): Brittle, non-conductor of electricity.

Solution:

• Sodium is a metal because it is shiny and reacts with water releasing hydrogen gas.
• Sulfur is a non-metal because it is brittle and a poor conductor.

This example shows how to use physical and chemical properties for classification.