Class 7 Science - ANDHRA-PRADESH
The World of Metals and Non-metals
In the chapter 'The World of Metals and Non-metals', Class 7 students of Andhra Pradesh (BSEAP) explore the fascinating materials that make up our surroundings. You will learn to classify elements into metals and non-metals based on their physical and chemical properties such as malleability, ductility, conductivity, and sonority. The chapter also covers how metals and non-metals react with oxygen, water, and acids, and introduces important reactions like displacement. Understanding this chapter is crucial for board exams as it builds the foundational chemistry concepts required for higher classes and features regularly in school-level formative and summative assessments.
Start Learning FreeKey Concepts
Physical Properties of Metals
Metals are generally hard, lustrous (shiny), malleable (can be beaten into sheets), ductile (can be drawn into wires), and are good conductors of heat and electricity.
Physical Properties of Non-metals
Non-metals are generally soft, non-lustrous, brittle, and poor conductors of heat and electricity, existing in solid, liquid, or gaseous states at room temperature.
Reaction with Oxygen
Metals react with oxygen to form basic oxides, while non-metals react with oxygen to form acidic or neutral oxides.
Reaction with Acids
Most metals react with acids to produce metal salts and hydrogen gas, which burns with a pop sound, whereas most non-metals do not react with dilute acids.
Displacement Reactions
A more reactive metal displaces a less reactive metal from its salt solution in water.
Important Formulas
Board Exam Info
In the Andhra Pradesh (BSEAP) Class 7 Science examinations, this chapter typically carries around 6 to 8 marks. Questions commonly include fill-in-the-blanks, matching the following, short answer questions about physical and chemical properties, and reason-based questions like why electrical wires are made of copper.
Frequently Asked Questions
Why are copper and aluminum used to make electric wires?
Copper and aluminum are metals that are excellent conductors of electricity and are ductile, meaning they can be easily drawn into thin wires.
Why is sodium stored in kerosene?
Sodium is a very reactive metal that catches fire spontaneously when it comes in contact with moisture and oxygen in the air, so it is stored in kerosene to prevent exposure.
Can non-metals conduct electricity?
Most non-metals are poor conductors of electricity, but graphite (a form of carbon) is an exception and can conduct electricity.
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