According to Bohr's atomic theory :
(A) Kinetic energy of electron is $\propto {{{Z^2}} \over {{n^2}}}$.
(B) The product of velocity (v) of electron and principal quantum number (n), $'vn' \propto {Z^2}$.
(C) Frequency of revolution of electron in an orbit is $\propto {{{Z^3}} \over {{n^3}}}$.
(D) Coulombic force of attraction on the electron is $\propto {{{Z^3}} \over {{n^4}}}$.
Choose the most appropriate answer from the options given below :
Solution
According to Bohr's theory,<br/><br/>I. $KE \propto {{{Z^2}} \over {{n^2}}}$ or $13.6 \propto {{{Z^2}} \over {{n^2}}}{{(eV)} \over {(atom)'}}$<br/><br/> ($\therefore$ Correct)<br/><br/>II. Speed of electron $\propto {Z \over n}$<br/><br/>(Here, Z = atomic number, n = number of shells)<br/><br/>$\therefore$ $v \times n \propto Z$ ($\therefore$ Incorrect)<br/><br/>III. Frequency of revolution of electron $= {v \over {2\pi r}}$<br/><br/>Frequency $\propto {{{Z^2}} \over {{n^3}}}$ ($\because$ $v \propto {z \over n},r \propto {{{n^2}} \over z}$) ($\therefore$ Incorrect)
About this question
Subject: Chemistry · Chapter: Atomic Structure · Topic: Bohr's Model
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