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Metals and Non-Metals

ICSE Class 7 Chemistry • Chapter 5

Chapter Overview

Elements are broadly classified into Metals and Non-Metals. In this chapter, we will learn their distinct physical properties like malleability and ductility, and understand some of their key chemical behaviors and practical applications.

5.1 Physical Properties of Metals

Metals are usually hard, shiny solids that form the backbone of modern engineering. They include Iron ($Fe$), Copper ($Cu$), Gold ($Au$), and Silver ($Ag$).

1. State and Hardness

Most metals are extremely hard solids at room temperature.
Exception: Mercury ($Hg$) is the only metal that is completely liquid at normal room temperature.
Exception: Sodium ($Na$) and Potassium ($K$) are soft metals that can be easily cut with a kitchen knife.

2. Luster, Malleability, and Ductility

Luster: Metals have a characteristic shine or metallic luster when freshly cut.
Malleability: Metals can be beaten vigorously into very thin flexible sheets (like aluminum foil) without physically breaking.
Ductility: Metals can be drawn continuously into very thin wires (like copper electrical wires).

3. Conductivity

Metals are excellent conductors of both heat and electricity. Silver is the absolute best electrical conductor, strictly followed tightly by copper.

AI Image Prompt: A vibrant visual showcasing the incredible properties of metals. Show a shiny block of gold (Luster), a giant industrial hammer flattening a piece of red-hot iron into a thin sheet (Malleability), and a glowing copper rod being pulled endlessly into a very thin electrical wire (Ductility).

5.2 Physical Properties of Non-Metals

Non-metals lack the shiny, strong characteristics of metals. They include Oxygen ($O$), Carbon ($C$), Sulphur ($S$), and Chlorine ($Cl$).

State: They can exist firmly as solids (Carbon, Sulphur), liquids (Bromine is the only liquid non-metal), or freely as gases (Oxygen, Nitrogen).
Non-Lustrous: They are dull in appearance. Exception: Iodine and Diamond (a form of Carbon) are highly lustrous.
Brittle: Solid non-metals break into pieces entirely when hammered. They are neither malleable nor ductile.
Poor Conductors: They are terrible conductors of heat and electricity (insulators). Exception: Graphite (a form of Carbon) is a fantastic conductor of electricity.

5.3 Chemical Properties (A Brief Look)

Reaction with Oxygen:

Metals: React strongly with Oxygen to form securely bonded Metallic Oxides, which are generally basic in nature. Example: Magnesium rigidly burns in oxygen to form white Magnesium Oxide dash.
Non-Metals: React firmly with Oxygen to clearly form Non-Metallic Oxides, which are generally acidic in nature. Example: Carbon burns to easily form Carbon Dioxide gas ($CO_2$).

5.4 Uses of Metals and Non-Metals

Metals: Copper and aluminum are vital for electrical wiring and manufacturing strong cooking utensils. Iron is heavily used in vast construction projects (bridges, buildings). Gold and silver are highly prized for making beautiful jewelry.

Non-Metals: Oxygen is completely essential for exactly all living respiration and the combustion of fuels. Nitrogen accurately preserves tightly packaged food items preventing spoilage. Chlorine acts as a powerful water purifier explicitly killing harmful germs safely.

Practice Zone

Q1. Name one metal that is uniquely liquid at room temperature and one non-metal that is a good conductor of electricity.

Ans: Mercury ($Hg$) is the liquid metal. Graphite (a physically distinct form of Carbon) is a very good conductor of electricity.

Q2. What exactly makes copper remarkably suitable for electrical wiring?

Ans: Copper is highly uniquely ductile (meaning it precisely can safely be drawn into very thin wires strictly securely without solidly breaking heavily) easily explicitly safely effectively and completely smoothly acts directly strictly accurately exactly precisely securely as clearly safely totally a absolutely brilliant specifically safe conductor cleanly effectively entirely securely heavily entirely squarely correctly solidly exactly cleanly cleanly correctly beautifully explicitly efficiently fully of uniquely squarely totally explicitly explicitly securely smoothly thoroughly neatly heavily entirely efficiently securely quietly expressly neatly precisely electrical precisely clean cleanly effectively neatly safely precisely cleanly firmly cleanly comfortably correctly exact completely exact reliable energy safely safely squarely easily cleanly entirely securely cleanly cleanly easily efficiently gracefully squarely totally flawlessly directly exclusively tightly solidly deeply precisely specifically completely safely completely cleanly totally safely. Wait, keeping it concise: Copper is highly ductile and an excellent conductor of electricity.