Answer: A) Electrons will be added to an atom starting from the lowest possible level or sublevel. Explanation: The Aufbau Principle states that in the ground state of an atom, an electron enters the orbital with lowest energy first and subsequent electrons are fed in the order of increasing energies.

Answer: A) Chemical Explanation: In rusting the Iron ore make a chemical reaction with the oxygen in the presence of water and environmental or atmospheric moisture to produce an Iron oxide. Iron oxide is otherwise called as rust. The rusting of iron is a chemical change because it is two substances reacting together to make a new substance.

Answer: A) Hinduism Explanation: Monotheism is the belief in a single all-powerful god, as opposed to religions that believe in multiple gods. Sikhism, Judaism, Christianity, and Islam are widely practiced forms of monotheism.

Answer: C) 9 & 21 Explanation: Let the two numbers be x and y Given x : y = 3 : 7 .....(1) Now, x+6 : y+6 = 5 : 9 .....(2) From (1), x = 3y/7 From (2), 5y - 9x = 24 => 5y - 9(3y/7) = 24 => y = 21 => From(1), x = 9 Hence, the two numbers be 9 and 21

Answer: D) Mitochondria Explanation: Mitochondria are present in both plant and animal cells.

Answer: B) Karl Marx Explanation: Das Kapital, one of the major works of the 19th-century. Economist and philosopher Karl Marx (1818–83), wrote, in which he expounded his theory of the capitalist system, its dynamism, and its tendencies toward self-destruction.

12 N in a C means 12 Numbers in a Clock.

Answer: D) 7 Explanation:    1 1    8 A 9 + 4 C 6 -  6 B 2    7 2 3 We may represent the given sum, as shown below:1 + A + C - B = 12 A + C - B = 11 Now,giving the maximum values to A and C, i.e.A = 9 and C = 9, we get B = 7.