Calculate the wavelength of an electron (m = 9.11 × 10-28 g) moving at 3.66 × 106 m/s.

The answer is 1.99 × 10⁻¹⁰ m.

To calculate this we will use De Broglie wavelength formula:
λ = h/(m*v)
λ - the wavelength
h - Plank's constant: h = 6.626 × 10⁻³⁴ Js
v - speed
m - mass

It is given:
λ = ?
m = 9.11 × 10⁻²⁸ g
v = 3.66 × 10⁶ m/s

After replacing in the formula:
λ = h/(m*v) = 6.626 × 10⁻³⁴ /(9.11 × 10⁻²⁸ * 3.66 × 10⁶) = 1.99 × 10⁻¹⁰ m

You get 6 for mechanical