Chapter 4, Structure of the Atom
CBSE Board Class 9, NCERT Science (Chemistry)
Solutions of Chapter Intext Questions
Q.1: What are canal rays?
Q.2: If an atom contains one electron and one proton, will it carry any charge or not?
Q.3: On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole.
Q.4: On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q.5: Draw a sketch of Bohr’s Model of an atom with three shells.
Q.7: What do you think would be the observation if the α-particle scattering experiment is carried out using a foil of a metal other than gold?
Q.8: Name the three sub-atomic particles of an atom.
Q.9: Helium atom has an atomic mass of 4u and two protons in its nucleus. How many neutrons does it have?
Q.10: Write the distribution of electrons in carbon and sodium atoms.
Q.11: If K and L shells of an atom are full, then what would be the total number of electrons in the atom?
Q.12: How will you find the valency of chlorine, sulphur and magnesium?
Q.13: If the number of electrons in an atom is 8 and the number of protons are also 8, then (i) what is the atomic number of the atom? (ii) What is the charge on the atom?
Q.14: For the symbol H, D and T tabulate three subatomic particles found in each of them.
Q.15: Write the electronic configuration of any one pair of isotopes and isobars.
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