AFMC AFMC Solved Paper-2007

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

    A) Deuterium atom                             

    B) Hydrogen atom

    C) Doubly ionized lithium  

    D) Singly ionized helium

    Correct Answer: C

    Solution :

    Radius of nth Bohr's orbit of hydrogen like atom\[{{r}_{n}}\propto \frac{{{n}^{2}}}{Z}\]where, Z is 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