Grade -4 Podar International School, Gandhinagar

CH-14 POLLUTION KEY WORDS pollution garbage decay decibels poisonous chimneys decompose loudspeakers smoke residential biodegradable generators emitted dumping typhoid factories carpools chemicals diarrhoea deaf Define the terms 1.     Pollution: Pollution is the presence or introduction into the environment of a substance or thing that has harmful or poisonous effects. Q and A Q-1   How is noise pollution caused? A-1 Noise pollution is caused by:        1. Horns of vehicles.        2. Buzzers and hooters of factories.        3. Noises of people in the markets.        4. High volumes of TV and radio sets.        5. Jugging sound of scooters and generators.        6. Blaring of loudspeakers. Q-2   What are the effects of air pollution? Ans-2 Air pollution cau

PHYSICAL STATES OF MATTER KEY-WORDS particles volume pattern molecules container properties matter poured poured atom gaseous jiggle rigid liquid evaporation Define the terms 1.Matter: Anything that has weight and occupies space is a matter. 2.Atom: Every matter around us is made up of small particles known as atoms. 3. Molecules: Atoms combine to form molecules. 4. Solid: The state of matter in which a substance has a fixed shape and volume. 5. Liquid: The state of matter which has no fixed shape and the substance flow freely. 6. Gas: The state of matter in which the substance has no fixed shape and volume. Molecules move in all directions. Question And answers Q-1 Give three exa