Top 100 Important Everyday Science Mcqs Set-2 21- The chemical (ethyl mercaptan) added to the otherwise odorless LPG cooking gas for imparting a detectable smell to the gas is a compound of: A. SulphurB. FluorineC. ChlorineD. Bromine View Answer Answer : A. Sulphur Description 22- An element that does not occur in nature but can be produced artificially is: A. ThoriumB. RadiumC. PlutoniumD. Uranium View Answer Answer : C. Plutonium Description 23- The inert gas which is substituted for nitrogen in the air, used by deep sea divers for breathing is: A. XenonB. KryptonC. HeliumD. Argon View Answer Answer : C. Helium Description 24- The group of metals Fe, Co, Ni may be best called as: A. Alkali metals B. Rare metals C. Main group metals D. Transition metals View Answer Answer : D. Transition metals Description 25- Heavy water is: A. H₂O+SaltB. D₂OC. H₂O₂ D. Ca & Mg carbonates View Answer Answer : B. D₂O Description 26- Amalgams are: A. Alloys which contain carbon B. Alloys which have great resistance to abrasion C. Alloys which contain mercury as one of the contentsD. Highly coloured alloys View Answer Answer : C. Alloys which contain mercury as one of the contents Description 27- Which of the following characteristics is not shown by hydrogen? A. It supports combustionB. It burns in air to form water C. It readily combinesD. It combines with almost all the metals forming hydrides View Answer Answer : A. It supports combustion Description 28- Which of the following element is obtained from sea weeds? A. ArgonB. SulphurC. VanadiumD. Iodine View Answer Answer : D. Iodine Description 29- The metallic constituents of hard water are: A. Magnesium, calcium and tin B. Iron, tin and calcium C. Calcium, magnesium and ironD. Magnesium, tin and iron View Answer Answer : C. Calcium, magnesium and iron Description 30- The property of substance to absorb moisture from the air on exposure is called: A. OsmosisB. DesiccationC. EfflorescenceD. Deliquescence View Answer Answer : D. Deliquescence Description 31- Which gas is used for preparation of soda water? A. AmmoniaB. Carbon dioxideC. HydrogenD. Nitric oxide View Answer Answer : B. Carbon dioxide Description 32- Which of the following minerals has the lowest numerical hardness value? A. TalcB. GypsumC. ApatiteD. Topaz View Answer Answer : A. Talc Description 33- Brass gets discolored in air because of the presence of which of the following gases in air? A. NitrogenB. OxygenC. Carbon dioxideD. Hydrogen sulphide View Answer Answer : D. Hydrogen sulphide Description 34- Quartz crystal normally used in quartz clocks etc. are chemically: A. A mixtureB. Silicon dioxideC. GermaniumD. Sodium dioxide View Answer Answer : B. Silicon dioxide Description 35- Bell metal is an alloy of: A. Tin and copperB. Nickel and copperC. Zinc and copper D. Brass and nickel View Answer Answer : A. Tin and copper Description 36- The variety of coal in which the deposit contains recognizable traces of the original plant material is: A. BitumenB. PeatC. LigniteD. Anthracite View Answer Answer : B. Peat Description 37- The gas that usually causes explosions in coal mines is: A. AirB. LigniteC. HydrogenD. Methane View Answer Answer : D. Methane Description 38- In fireworks, the green flame is produced because of: A. BariumB. PotassiumC. SodiumD. Mercury View Answer Answer : A. Barium Description 39- Which of the following ores does not contain iron? A. HematiteB. MagnetiteC. CassiteriteD. Limonite View Answer Answer : C. Cassiterite Description 40- The element required for solar energy conversion is: A. UraniumB. SiliconC. SeleniumD. Germanium View Answer Answer : B. Silicon Description 1 2 3 4 5