1.	Mendeleev could not assign a correct position to which of the following elements in his table ?
	Lithium
	Potassium
	Hydrogen
	Helium
	Answer: Hydrogen Explanation: The position of hydrogen was not justified in Mendeleev's periodic table. He positioned hydrogen in the first column above alkali metal. Hydrogen resembles not only alkali metals but also halogens in several ways. Hence, hydrogen can also be placed above the halogen group
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2.	Who demonstrated that objects of different masses would reach the ground together when dropped from the same height ?
	Isaac Newton
	Archimedes
	Robert Boyle
	Galileo Galilei
	Answer: Galileo Galilei Explanation: According to Galileo Galilei, if objects of different masses are dropped from the same height in the absence of air resistance the bodies will ground together at the same time
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3.	Which of the following, can neither be created nor be destroyed ?
	Force
	Power
	Momentum
	Energy
	Answer: Energy Explanation: The first law of thermodynamics, also known as Law of Conservation of Energy, states that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another
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4.	Mass / Volume = .............. ?
	Pressure
	Area
	Density
	Force
	Answer: Density Explanation: The density of a substance is its mass per unit volume
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5.	A mixture of sand and salt can be separated by ?
	Sublimation
	Sieving
	Dissolving salt in water and then filtration
	Dissolving salt in water and then distillation
	Answer: Dissolving salt in water and then distillation Explanation: the water to boil away and collect salt from there. Hence, we can separate sand and salt by Dissolving salt in water and then distillation
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6.	Which of the following has low density and low melting point ?
	Na
	Fe
	Cu
	Au
	Answer: Na Explanation: Sodium
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7.	If the electronic configuration of an element is 2, 8, 2, to which period of the Modern Periodic Table does it belong ?
	4
	2
	12
	3
	Answer: 3 Explanation: Element with electronic configuration 2,8,2 belongs to 3rd period and 2nd group. The valence electrons give us the idea of group number. As the electrons are divided into 3 different shell therefore period number is 3
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8.	1 joule / second = ?
	1 ohm
	1 ampere
	1 watt
	1 coulomb
	Answer: 1 watt Explanation: one joule per second is equivalent to one watt. The SI units for work and time are Joules and seconds, respectively. Therefore, One Watt was defined as a power of 1 Joule per second
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9.	Modern periodic table is based on .......... ?
	atomic number
	number of positrons
	atomic mass number
	number of neutrons
	Answer: atomic number Explanation: The modern periodic table is based on the periodic law: "The chemical properties of elements are a periodic function of their atomic number."
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10.	A boy, of mass 50 kg, runs up a staircase of 45 steps in 10 s. If the height of each step is 14 cm, find his power. Take g= 10ms-2 ?
	315 ms
	315 W
	337.5W
	310.55 J
	Answer: 315 W Explanation: Given, the mass of the body, m = 50 kg. h is the height, t is the time. g is the acceleration due to gravity which is aproximated to 10 m/s2 ? h = 45 × 14 = 630 cm = 6.30 m ? t = 10 s, g = 10 ms-2 ? Potential Energy = mgh = 50 × 10 × 6.30 = 3150 J. (where J is the unit of energy/work which is joules) ? Power = PE / time = Energy / time = 3150 / 10 = 315 watt. (watt is the unit of power which is different from units)
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