Structure Of Atom

  • Question
    CBSEENCH11008051

    Which of the following is the energy of a possible excited state of hydrogen?

    • +13.6 eV

    • -6.8 eV

    • -3.4 eV

    • +6.8 eV

    Solution

    C.

    -3.4 eV

    Since at n=1 the population of electrons is maximum i.e. at the ground state. So, maximum excitation will take place from n = 1 to n=2.
    Hence, n=2 is the possible excited state,
    Now, we have the formula for energy of H-atom
    (En)H = negative 13.6 straight Z squared over straight n squared eV
    where Z = atomic number 
    Z for H-atom = 1
    therefore, (En)H  = 13.6 space straight x space 1 over 2 squared eV space equals space 136 over 4 eV space equals negative 3.4 eV

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