2. Solved Papers
  3. NEET
  4. Physics
  5. Atomic Physics

NEET Physics Atomic Physics NEET PYQ-Atomic Physics

  • question_answer
    In which of the following systems will the radius of the first orbit \[(n=1)\] be minimum?                       [AIPMT 2003]

    A)        Deuterium atom

    B)                   Hydrogen atom

    C)  Doubly ionized lithium

    D)  Singly ionized helium

    Correct Answer: A

    Solution :

    Radius of nth Bohr’s orbit of hydrogen like atom, \[{{r}_{n}}\propto \frac{{{n}^{2}}}{Z}\]
                Where, \[Z\] s atomic number, for first orbit \[n=1\]
                \[\therefore \]      \[{{r}_{n}}\propto \frac{1}{Z}\]
    Now, for radius of first orbit to be minimum, its atomic number must be greater. Here in the problem, atomic number Z is greater for doubly ionized lithium and is \[Z=3\]. Hence, for this system the radius of first orbit will be minimum.


You need to login to perform this action.
You will be redirected in 3 sec spinner