Class 7, Science ( English )

Class 7 : Science – ( English ) : Lesson 4. The World of Metals and Non-metals

STUDYZONE PRO  •  Science

Metals and Non-Metals

Understanding the two great families of elements

Everything around us is made of elements. Scientists divide most elements into two main groups based on how they look and behave: metals and non-metals. Learning the difference helps us understand why a coin feels cold and shiny, while a piece of coal is dull and crumbly.

1. Metals — Example: Gold

Gold, a shiny lustrous metal used as an example of a metal element

Gold is a classic example of a metal. Metals share a set of common properties that make them easy to recognise:

  • Lustrous (shiny): Metals like gold have a bright, polished shine.
  • Malleable: They can be hammered into thin sheets without breaking.
  • Ductile: They can be drawn into thin wires.
  • Good conductors: Metals conduct heat and electricity well.
  • Hard & strong: Most metals are solid at room temperature (mercury is the exception).
  • Sonorous: They make a ringing sound when struck.

2. Non-Metals — Example: Carbon

Carbon, a dull non-metal element shown as an example of a non-metal

Carbon is a common example of a non-metal. Non-metals behave very differently from metals:

  • Dull appearance: Most non-metals have no shine (graphite is an exception).
  • Brittle: Solid non-metals break or crumble when hammered.
  • Not ductile: They cannot be drawn into wires.
  • Poor conductors: Non-metals are generally bad conductors of heat and electricity (graphite is an exception).
  • Varied states: They may be solid, liquid, or gas at room temperature.
  • Not sonorous: They do not produce a ringing sound.

Quick Comparison

Property Metals (e.g. Gold) Non-Metals (e.g. Carbon)
LustreShinyDull
MalleabilityMalleableBrittle
DuctilityDuctileNon-ductile
ConductivityGood conductorPoor conductor
SoundSonorousNot sonorous
State at room temp.Mostly solidSolid, liquid or gas

Remember

A few elements show mixed behaviour and are called metalloids (for example, silicon and boron). Also, some exceptions exist — graphite (a form of carbon) conducts electricity, and mercury (a metal) is a liquid.

© STUDYZONE PRO  •  www.studyzonepro.com  •  Study material for Class 6–12

Leave a Reply