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Helium atom has an atomic mass of 4 u an...

Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?

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Mass number of helium = 4 Number of protons = 2 Number of neutrons (n) Mass number (A) - No. of protons (p) = 4 - 2 = 2 Thus, no. of neutrons = 2
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MTG IIT JEE FOUNDATION-STRUCTURE OF THE ATOM-NCERT SECTION
  1. What do you think would be the observation if the alpha-particle scatt...

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  2. Name the three sub-atomic particles of an atom.

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  3. Helium atom has an atomic mass of 4 u and two protons in its nucleus. ...

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  4. Write the distribution of electrons in carbon and sodium atoms.

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  5. If K and L shells of an atom are full, then what would be the total nu...

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  6. How will you find the valency of chlorine, sulphur and magnesium ?

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  7. If number of electrons in an atom is 8 and number of protons is also 8...

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  8. If number of electrons in an atom is 8 and number of protons is also 8...

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  9. Atomic numbers of oxygen and sulphur are 8 and 16 respectively. Oxygen...

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  10. Write the electronic configuration of any one pair of isotopes and iso...

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  11. For the symbol H,D and T tabulate three sub-atomic particles found in ...

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  12. Compare the properties of electrons, protons and neutrons.

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  13. What are the limitations of J.J. Thomson’s model of the atom?

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  14. What are the limitations of Rutherford's model of the atom ?

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  15. Describe Bohr's model of the atom.

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  16. Compare all the proposed models of an atom given in this chapter.

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  17. Summarise the rules for writing of distribution of electrons in variou...

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  18. Define valency by taking examples of silicon and oxygen.

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  19. Explain with examples Atomic number Give any two uses of isotopes...

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  20. Explain with examples Mass number Give any two uses of isotopes.

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