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]
-
A.
3.63 x 10-19m -
B.
6.51 x 10-9m -
C.
4.24 x 10-8m -
D.
7.25 x 10-8m
Correct Answer: Option 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