Question

A microscope using suitable photons is employed to locate an electron in an atom within a distance of $0.1\mathring{A}$. The uncertainty of its velocity is

• A. $5.79\times {10}^{5}m{s}^{-1}$
• B. $8.79\times {10}^{5}m{s}^{-1}$
• C. $5.79\times {10}^{4}m{s}^{-1}$
• D. $3.79\times {10}^{5}m{s}^{-1}$

Answer 1

The correct option is A $5.79\times {10}^{5}m{s}^{-1}$

According to Heisenberg's Uncertainty principle,

$m=9.11\times {10}^{-31}kgh=6.626\times {10}^{-34}Js$

$\Delta v=\frac{h}{4\pi m\Delta x}$

$\Delta v=\frac{6.626\times {10}^{-34}}{4\times 3.14\times 9.11\times {10}^{-31}\times 0.1\times {10}^{-10}}$

$\Delta v=5.79\times {10}^{6}m/s$