an electron moves with a speed of 2.0 x 106ms-1 in a straight line. Calculate the wave length of the electron wave. [mass of an electron = 9.1 x 10-31 kg][Planck’s constant = 6.6 x 10-34Js]
- 3.63 x 10-19m
- 6.51 x 10-9m
-
4.24 x 10-8m
- 7.25 x 10-8m
The correct answer is: C
Explanation
\(\lambda = \frac{hc}{\frac{1}{2}mv^2} = \frac{6.6 \times 10^{-38} \times 3 \times 10^8}{\frac{1}{2} \times 9.1 \times 10^{-31} (2 \times 10^6)^2}\)= 4.24 x 10-8m