Q. Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron
to be found within an atomic nucleus of diameter 10−15 m is
_____ × 109 m s−1 (nearest integer).
Given : mass of electron = 9.1 × 10−31 kg
Planck's constant (h) = 6.626 × 10−34 J s
Value of π = 3.14
Explanation
Step 1: Heisenberg Uncertainty Principle
Δx · Δp ≥ h / 4π
Step 2: Convert momentum uncertainty to velocity
Δp = m · Δv
Δv ≥ h / (4π m Δx)
Step 3: Substitute values
Δx = 10−15 m
m = 9.1 × 10−31 kg
Δv ≥ 6.626 × 10−34 / (4 × 3.14 × 9.1 × 10−31 × 10−15)
Δv ≈ 5.8 × 1010 m s−1
Correct Answer = 58