Science MCQ Structure of the Atom Chapter 4 Class 9 Advertisement MCQ’s For All Chapters – Science Class 9th 1. Which of the following atoms has a valency of two?SodiumMagnesiumAluminiumChlorineQuestion 1 of 202. If an element has electronic configuration 2,8,2, its atomic number is10121416Question 2 of 203. An atom of aluminium has atomic number 13.How many electrons are in its M shell?1234Question 3 of 204. Which of the following has the highest number of neutrons?¹H²H³H⁴HeQuestion 4 of 205. Which statement about isotopes is incorrect?They have same number of protonsThey have different atomic numbersThey have different mass numbersThey have same chemical propertiesQuestion 5 of 206. The average atomic mass of chlorine is 35.5 u.Which statement explains this?Chlorine atoms have fractional massChlorine occurs as a mixture of ³⁵Cl and ³⁷ClEach atom weighs 35.5 u³⁷Cl does not existQuestion 6 of 207. A neutral atom of calcium (atomic number 20) has how many electrons in the L shell?281018Question 7 of 208. If an atom has 3 shells completely filled, what will be its total number of electrons?10182832Question 8 of 209. The atom of an element X has 6 protons and 8 neutrons.The symbol of the element is¹⁴₆X⁶₁₄X¹²₆X⁸₆XQuestion 9 of 2010. Which element forms an ion with configuration 2,8?SodiumNeonOxygenChlorineQuestion 10 of 2011. An atom has mass number 31 and atomic number 15.The number of neutrons is15163146Question 11 of 2012. The number of nucleons in an atom with atomic number 17 and mass number 35 is17183552Question 12 of 2013. Which of the following pairs represents isobars?¹⁴₆C and ¹⁴₇N²₁H and ³₁H³⁵₁₇Cl and ³⁷₁₇Cl¹²₆C and ¹⁴₆CQuestion 13 of 2014. How many electrons can be present in the M shell?818322Question 14 of 2015. Which statement correctly describes Rutherford’s model?Positive charge spread evenlyElectrons embedded in sphereMost mass concentrated in tiny nucleusElectrons stationary inside nucleusQuestion 15 of 2016. The major limitation of Rutherford’s model was that it could not explainPosition of electronsStability of atomExistence of nucleusMass of atomQuestion 16 of 2017. If number of protons = number of electrons = 8, the atom isNeutralPositively chargedNegatively chargedUnstableQuestion 17 of 2018. What will be the mass number of an atom with 11 protons and 12 neutrons?11122324Question 18 of 2019. How many neutrons are present in ¹⁴₆C?6789Question 19 of 2020. The isotope of uranium used in nuclear reactors is²³⁸₉₂U²³⁵₉₂U²³²₉₀Th²³⁹₉₄PuQuestion 20 of 20 Loading...
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