Structure of the Atom
1. Compare the properties of electrons, protons and neutrons.
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2. What are the limitations of J.J Thomson's model of the atom?
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3. What are the limitations of Rutherford's model of the atom?
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4. Describe Bohr's model of the atom.
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5. Compare all the proposed models of an atom given in this chapter.
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6. Summarise the rules for Writing of distribution of electrons in various shells for the first eighteen elements.
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7. Define valency by taking examples of silicon and oxygen.
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8. Explain with examples (i) Atomic number, (ii) Mass number, (iii) Isotopes and (iv) Isobars. Give any two uses of isotopes.
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9. Na has completely filled K and L shells. Explain.
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10. If bromine atom is available in the form of, say, two isotopes
79 Br (49.7%) and 81 Br (50. 3%), calculate the average atomic
35 35
mass of bromine atom.
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11. The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes 16 X and 18 X in the sample?
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12. If Z=3, what would be the valency of the element? Also, name the element.
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13. Composition of the nuclei of two atomic species X and Y are given as under
X Y
photons = 6 6
Neutrons = 6 8
Give the mass numbers of X and Y. what is the relation between the two species?
14. For the following statements, write T for True and F for False.
(a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons.
(b) A neutron is formed by an electron and a proton combining together. therefore, it is neutral.
Post ID: DABP001678
