81. Which of the following is an element? September 19, 2025 by Admin A. Ruby B. Sapphire C. Emerald D. Diamond ✅ The correct answer is option D.
82. Soda water contains September 19, 2025 by Admin A. carbonic acid B. sulphuric acid C. carbon dioxide D. nitrous acid ✅ The correct answer is option C.
83. Bell metal is an alloy of September 20, 2025 by Admin A. nickel and copper B. zinc and copper C. brass and nickel D. tin and copper ✅ The correct answer is option D.
84. The chemical (ethyl mercaptan) added to the otherwise odourless LPG cooking gas for imparting a detectable smell to the gas is a compound of September 20, 2025 by Admin A. bromine B. fluorine C. chlorine D. sulphur ✅ The correct answer is option D.
85. LPG consists of mainly September 20, 2025 by Admin A. methane, ethane and hexane B. ethane, hexane and nonane C. methane, hexane and nonane D. methane, butane and propane ✅ The correct answer is option D.
86. The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is September 20, 2025 by Admin A. Argon B. Xenon C. Helium D. Krypton ✅ The correct answer is option C.
87. Which of the following is in liquid form at room temperature? September 20, 2025 by Admin A. Lithium B. Sodium C. Francium D. Cerium ✅ The correct answer is option C.
88. Which of the following are the ingredients of gun metal? September 20, 2025 by Admin A. Iron, Zinc, Titanium B. Iron, tin C. Iron, Brass, Tin D. Copper, Tin ✅ The correct answer is option D.
89. Quartz crystals normally used in quartz clocks etc. is chemically September 20, 2025 by Admin A. silicon dioxide B. germanium oxide C. a mixture of germanium oxide and silicon dioxide D. sodium silicate ✅ The correct answer is option A.
90. Amalgams are September 20, 2025 by Admin A. highly coloured alloys B. alloys which contain mercury as one of the contents C. alloys which have great resistance to abrasion D. alloys which contain carbon ✅ The correct answer is option B.