Answer 1

According to de Broglie’s equation,

`lambda = h/(mv)`

λ = wavelength of moving particle

m = mass of particle

v = velocity of particle

h = Planck’s constant

Substituting the values in the expression of λ:

`lambda = (6.626 xx 10^(-34) Js)/((9.10939xx10^(-31)kg)(2.05xx10^7 ms^(-1)))

`lambda = 3.548 xx 10^(-11)m`

Hence, the wavelength of the electron moving with a velocity of 2.05 × 10⁷ ms^–1 is 3.548 × 10^–11 m.