TOPIC The Classification of Substances Flammability Conduction of

TOPIC • The Classification of Substances: Flammability, Conduction of Electricity &Heat and Magnetic Nature • Teaching Points: (i) Flammability • (ii) Conduction of Electricity and Heat • (iii) Magnetic Nature

Specific Aim • : (i) To appreciate how the classification is done based on Flammability, Conduction of • Electricity &Heat and Magnetic Nature. • (ii) To know about Ignition temperature • (iii) To know the difference between Conductors and Insulators of heat and electricity • (iv) To know about Magnetic and Non-magnetic substances.

PREVIOUS KNOWLEDGE TEST • • • • • Question: Name few substances that catch fire. Answer: Few substances that catch fire are Paper, Petrol, Diesel, Kerosene, LPG (Liquid Petroleum Gas) etc. Question: Name few substances that are used to put out fire. Answer: Sand, Water etc. are the few substances used to put out fire. Question: Name few substances that are used to make handles of vessels and other kitchen implements. Answer: Substances that are used to make handles of vessels and other kitchen implements are Wood, Plastic etc. Question: Name three elements that are magnetic in nature. Answer: The elements that are magnetic in nature are Iron, Cobalt and Nickel. Question: Name three materials that are non-magnetic. Answer: Three materials that are non-magnetic are Wood, Plastic and Copper.

INTRODUCTION • You know cadets; • All substances need to be heated to a certain temperature before they catch fire. • Not all materials can carry heat and electricity through them. • Magnets can attract objects made of Iron, Cobalt and Nickel. • Today, we shall discuss about Flammability, Conduction of Electricity and Heat and Magnetic nature.

FLAMMABILITY Flammability: Flammability means ability to catch fire. o Flammable or Combustible substances: The substances that catch fire are known as flammable or combustible substances. e. g. Paper, Petrol, Diesel, Kerosene, LPG (Liquid Petroleum Gas) etc. o Non-Flammable or Non-Combustible substances: The substances that do not catch fire are known as nonflammable or non-combustible substances. Sand, Water etc.

Conduction of Electricity and Heat: Conduction of Electricity and Heat means ability to allow heat and electricity to pass through any material. o Conductors of Heat and Electricity: The materials which allow both heat and electricity to pass through them are known as conductors of heat and electricity. e. g. Copper, stainless steel, Aluminium etc. o Insulators of Heat and Electricity: The materials which neither allow heat nor electricity to pass through them are known as insulators of heat and electricity. e. g. Wood, Paper, Plastic etc.

Magnetic nature: Magnetic nature means ability to be attracted by a magnet. o Magnetic materials: The materials that are attracted by a magnet are known as magnetic materials. e. g. Iron, Cobalt and Nickel. o Non-magnetic materials: The materials that are not attracted by a magnet are known as non-magnetic materials. e. g. Wood, Plastic, Copper etc.

SOME QUESTIONS AND ANSWERS Question: Define: Flammability. Answer: Flammability means ability to catch fire. Question: Differentiate between Flammable and Non-flammable substances. Answer: Flammable or Combustible substances: The substances that catch fire are known as flammable or combustible substances. e. g. Paper, Petrol, Diesel, Kerosene, LPG (Liquid Petroleum Gas) etc. • Non-Flammable or Non-Combustible substances: The substances that do not catch fire are known as non-flammable or non-combustible substances. Sand, Water etc. • •

SOME QUESTIONS AND ANSWERS • • • Question: What do you mean by conduction of heat and electricity? Answer: Conduction of Electricity and Heat means ability to allow heat and electricity to pass through any material. Question: Differentiate between conductors and insulators of heat and electricity. Answer: Conductors of Heat and Electricity: The materials which allow both heat and electricity to pass through them are known as conductors of heat and electricity. e. g. Copper, stainless steel, Aluminium etc. Insulators of Heat and Electricity: The materials which neither allow heat nor electricity to pass through them are known as insulators of heat and electricity. e. g. Wood, Paper, Plastic etc.

Question? • Question: Differentiate between Magnetic and Non-magnetic materials. • Answer: Magnetic materials: The materials that are attracted by a magnet are known as magnetic materials. e. g. Iron, Cobalt and Nickel. • Non-magnetic materials: The materials that are not attracted by a magnet are known as non- Magnetic materials. e. g. Wood, Plastic, Copper etc.