science important bits which we get in all exams

1.	Brass gets discoloured in air because of the presence of which of the following gases in air?
	A. Oxygen B. Hydrogen sulphide C. Carbon dioxide D. Nitrogen Answer & Explanation Answer: Option B Explanation:

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2.	Which of the following is a non metal that remains liquid at room temperature?
	A. Phosphorous B. Bromine C. Chlorine D. Helium Answer & Explanation Answer: Option B Explanation:

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3.	Chlorophyll is a naturally occurring chelate compound in which central metal is
	A. copper B. magnesium C. iron D. calcium Answer & Explanation Answer: Option B Explanation:

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4.	Which of the following is used in pencils?
	A. Graphite B. Silicon C. Charcoal D. Phosphorous Answer & Explanation Answer: Option A Explanation:

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5.	Which of the following metals forms an amalgam with other metals?
	A. Tin B. Mercury C. Lead D. Zinc Answer & Explanation Answer: Option B Explanation: No answer description available for this question.