Physical and chemical changes
Assignment
Class - 7
1.
A change in which a substance undergoes changes in its physical
properties is called ( )a. Chemical change b. Physical change. c No change d. Biological change
2. When carbon dioxide is passed through lime water , then lime water becomes ( )
a. milky b. Shiny c. Silver d. Golden yellow
3. Brown colour of the apple after cutting is ( )
a. physical change b. chemical change c. no change d. biological change
4. Ozone layer protects us from harmful ( )
a. Ultraviolet radiation b. Infrared Radiation c. Visible Radiation d. Heatradiation
5. The process of depositing a layer of one metal over another metal surface to protect it from rusting is called ( )
a. Galvanisation b. Crystallisation c. Amalgamating d. Neutralisation
6. For protecting iron pipes from corrosion, they are coated with
a. Zinc b. Copper c. Aluminium d. Silver
7. Metal that is made by mixing iron with carbon, nickel and manganese is called ( )
a. Stainless steel b. German silver c. Nichrome d. Eureka
8. The process of obtaining Salt by the evaporation of sea water is called ( )
a. Crystallisation b. Neutralisation c. Galvanisation d. Amalgamation
9. Blue colour of the copper sulphate solution changes to Green colour when an iron nail is dropped into it due to the formation of ( )
a. Iron sulphate b. copper chloride c. Copper iron sulphate d. Iron chloride
10. When Magnesium ribbon is burnt in oxygen, the product obtained is ( )
a. Magnesium chloride b. Magnesium sulphate c. Magnesium oxide d. Iron chloride
11. Magnesium hydroxide, obtained when Magnesium oxide is dissolved in water, is ( )
a. Base b. An acid c. an indicator d. a dissolving agent
12. When Magnesium ribbon is burnt in candle flame it burns with ( )
a. brilliant red light b. Brilliant yellow light c. Brilliant white light d. Brilliant Green light
