Revision Guide: The World of Metals and Non-metals
The World of Metals and Non-metals - Quick Look Revision Guide
Your 1-page summary of the most exam-relevant takeaways from Curiosity.
This compact guide covers 20 must-know concepts from The World of Metals and Non-metals aligned with Class 7 preparation for Science. Ideal for last-minute revision or daily review.
Revision guide
Complete study summary
Essential formulas, key terms, and important concepts for quick reference and revision.
Key Points
Define metals and provide examples.
Metals are lustrous, malleable, ductile, and good conductors. Examples include iron, copper, and gold.
Define non-metals and provide examples.
Non-metals are dull, brittle, and poor conductors. Examples include sulfur, carbon, and oxygen.
Explain malleability with examples.
Malleability is the ability to be shaped. Metals like gold and silver can be made into thin sheets.
Explain ductility with examples.
Ductility is the ability to be drawn into wires. Gold can be stretched into a wire up to 2 km long.
What is sonority?
Sonority is the ringing quality of sound. Metals like coins and bells exhibit this property.
State the conduction of heat in metals.
Metals conduct heat efficiently, making them ideal for cooking vessels. Wood does not conduct heat well.
State the conduction of electricity in metals.
Metals are good electrical conductors, allowing current to flow. Non-metals like sulfur do not conduct electricity.
What is rusting?
Rusting is the corrosion of iron due to moisture and air, leading to brown deposits. It can be prevented by painting.
Explain the significance of the Iron Pillar of Delhi.
The Iron Pillar shows advanced metallurgy. It's over 1600 years old with minimal rust, indicating expert skills.
What are metal oxides?
Metal oxides are generally basic and formed when metals react with oxygen. Example: Fe₂O₃.
What are non-metal oxides?
Non-metal oxides are usually acidic. For instance, SO₂ forms sulfurous acid in water.
State the effect of air on metals.
Metals can corrode when exposed to air, especially when combined with water. Example: rusting of iron.
Contrast metal and non-metal properties.
Metals are usually shiny and hard; non-metals are dull and brittle. This affects their applications.
Discuss the importance of metals in society.
Metals are essential in tools, construction, and technology. Their properties make them irreplaceable.
Explain the role of non-metals in life.
Non-metals like oxygen and nitrogen are vital for life and agriculture, supporting the ecosystem.
Define corrosion.
Corrosion is the gradual destruction of metals due to chemical reactions with environment, like rusting.
What is galvanization?
Galvanization involves coating iron with zinc to prevent rusting, an important protective measure.
List common uses of metals.
Common uses include construction materials, cookware, electronic devices, and vehicle parts.
Explain why sodium is stored in kerosene.
Sodium reacts violently with air and water, so it’s stored in kerosene to prevent such reactions.
How do non-metals differ in chemical reactions?
Non-metals typically form acids with oxygen and do not react with water like metals do, showing distinct chemistry.
