NEET-XII-Physics
43: Bohr's Model and Physics of the Atom
- #5In which of the following systems will the radius of the first orbit (n = 1) be minimum?
(a) Hydrogen atom
(b) Deuterium atom
(c) Singly ionized helium
(d) Doubly ionized lithiumdigAnsr: dAns : (d) Doubly ionized lithium
For a hydrogen-like ion with Z protons in the nucleus, the radius of the nth state is given by
`` {r}_{\,\mathrm{\,n\,}}=\frac{{n}^{2}{a}_{0}}{Z}``
Here, a0 = 0.53 pm
For lithium,
Z = 3
Therefore, the radius of the first orbit for doubly ionised lithium will be minimum.
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