Atomic Structure - Result Question 50
26. The energy of an electron in the first Bohr orbit of H-atom is $-13.6 $ $eV$. The possible energy value(s) of the excited state(s) for electrons in Bohr orbits of hydrogen is (are)
(1998,2 M)
(a) $-3.4 $ $eV$
(b) $-4.2 $ $eV$
(c) $-6.8 $ $eV$
(d) $+6.8 $ $eV$
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Answer:
Correct Answer: 26. (a)
Solution:
- The energy of an electron in a Bohr atom is expressed as
$ \begin{aligned} E _n=-\frac{k Z^{2}}{n^{2}} \quad \text { where, } \begin{aligned} k & =\text { Constant } \\ Z & =\text { Atomic number, } \\ n & =\text { Orbit number } \end{aligned} \end{aligned} $
$ \hspace{10mm} =-13.6 $ $eV \text { for } H(n=1)$
when $n=2, E _2=\dfrac{-13.6}{2^{2}}$ $ eV=-3.40$ $ eV$
( $n$ can have only integral value $1,2,3, \ldots \ldots \infty$ )
BETA
