Question

Calculate wavelength of electron having 2.05 × 10⁻⁷ ms⁻¹ velocity.

Answer 1

we know,

mass of electron ( m ) = 9.1 × 10^-31 Kg

Plank's constant ( h ) = 6.626 × 10^-34 Js

velocity of electron ( v ) = 2.05 × 10^7 m/s

according to De - broglie's wavelength,

λ = h/mv

= 6.626 × 10^-34 Js /s/9.1 × 10^-31 Kg × 2.05 × 10^7 m/s

= 0.35 × 10^-10 m

= 0.35 A°

hence, wavelength of electron = 0.35 A° or, 3.5 × 10^-11 m

Hope it helps you..

Answer 2

Answer:

3.55 × 10`-11 m/s.

Explanation:

Velocity of an electron = 2.05 × 107 ms–1  (Given)

According to the de - Broglie’s Equation:

λ = h/mv

Where,

λ is the wavelength of moving particle, m is the mass of electron and v is the velocity of particle

h = Planck’s constant = [6.62× 10`-34]

Therefore,

λ = [6.62 × 10`-34] / [9.1× 10`-31] × [2.05 × 10`7]

λ  = [6.62× 10`-34] / [1.8655 × 10`-23]

λ = 3.55 × 10`-11

Thus, the  wavelength of the electron is 3.55 × 10-11 m