Final answer:
The average speed of the electron in the ground-state of hydrogen is estimated to be 10^-10 m/s. This is a very small fraction of the speed of light.
Step-by-step explanation:
The Heisenberg uncertainty principle states that it is impossible to simultaneously know the exact position and velocity of a subatomic particle. In the ground-state of hydrogen, the uncertainty in the electron's position is approximately 10^-10 m. Since the electron's speed in the ground state is roughly equal to the uncertainty in its velocity, we can estimate the average speed to be approximately 10^-10 m/s.
To determine the fraction of the speed of light, we can use the equation:
fraction of the speed of light = (average speed of electron) / (speed of light)
Substituting the values, we get:
fraction of the speed of light = (10^-10 m/s) / (3 x 10^8 m/s)
which simplifies to:
fraction of the speed of light ≈ 3.33 x 10^-19