1 The element present in the largest amount in rocks and minerals is —   1 Carbon 2 Silicon 3 Hydrogen 4 Aluminium   Answer: Option2

2 Permanent hardness of water can be removed by adding–   1 Potassium Permanganate 2 Chlorine 3 Bleaching Powder 4 Washing Soda   Answer: Option4

3 What is laughing gas?   1 Nitrous Oxide 2 Carbon monoxide 3 Sulphur dioxide 4 Hydrogen peroxide   Answer: Option1

4 Which of the following substances is not biodegradable?   1 Paper 2 Food refuse 3 Styrofoam 4 Sawdust   Answer: Option1

5 Stainless steel is an alloy of —   1 Iron, Carbon and Nickel 2 Iron and Manganese 3 Iron, Chromium and Zinc 4 Iron, Chromium and Nickel   Answer: Option4

6 Palaeobotany is the branch of botany is which we study about–   1 Animal fosills 2 Plant fossils 3 Seed of plant 4 Flower   Answer: Option2

7 Caustic Soda is —   1 Nacl 2 Na2CO3 3 NaOH 4 NaHCO3   Answer: Option3

8 Which of the gas is not known as green house gas?   1 Methane 2 Nitrous oxide 3 Carbon dioxide 4 Hydrogen   Answer: Option4

9 10.Silviculture is the branch of botany in which we study about–   1 Culture of algae 2 Development of forest 3 Culture of fungi 4 Silciphida plant   Answer: Option2

10 21. Which of the following is used as a material for making protective windows in space probes   1 Steel 2 Graphite 3 Tungsten 4 Diamond   Answer: Option4