Answer: D) All of the above Explanation: The halogens make up group 17 in the periodic table. They are five elements: Chlorine (Cl) Fluorine (F) Bromine (B) Iodine (I) Astatine (At). But astatine is not purely halogen as it is radioactive.

Answer: C) Nucleic acids Explanation: DNA stands for Deoxyribo nucleic acid. It is a nucleic acid made up of monomeric unit called Nucleotide. A nucleotide consist of - a) Sugar - Deoxyribose in DNA ( ribose in RNA) b) An organic base- Adenine, cytosine, guanine.

Answer: B) Potential energy Explanation: An object at rest may have Potential energy.

Answer: C) Mesosphere Explanation: The mesosphere lies above the stratosphere and extends to an altitude of about 85 km. This is layer is often referred to as the cold layer, as the lowest readings in the atmosphere are found here.   Temperature decreases with height, reaching a minimum average value of -90 ºC at the top of the layer.

Answer: C) 25 Explanation: According to BODMAS rule, After multiplication only, addition is done. Hence, 5 + 2 x 10 = 5 + 20 = 25.

Answer: A) 8400 Explanation: 12% of 70,000 => 12 x 70,000/100 => 8400   Hence, 12% of 70,000 = 8,400

I am Keyboard. A Keyboard has keys of letters, space button and enter button.

Answer: D) All of the above Explanation: A metalloid is any chemical element which has properties in between those of metals and nonmetals, or that has a mixture of them. The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium.