What is the de Broglie wavelength of an electron traveling at 1.43×105m/s?

5.024 × 10⁻⁹ m

Explanation:

You need to use de Broglie's equation.

λ = h/mv

You have the velocity of the electron (1.43 × 10⁵ m/s), the mass of an electron (9.1 × 10⁻³¹ kg), and Planck's constant (6.626 × 10⁻³⁴ J·s).  You now need to solve for wavelength (λ).

λ = (6.626 × 10⁻³⁴ J·s)/(9.1 × 10⁻³¹ kg)(1.43 × 10⁵ m/s)

λ = 5.024 × 10⁻⁹ m

The de Broglie wavelength is 5.024 × 10⁻⁹ m.

h

dynamic equilibrium is the answer.