## Post-Module Q#18

$\Delta p \Delta x\geq \frac{h}{4\pi }$

Jessica Dharmawan 1G
Posts: 32
Joined: Fri Sep 28, 2018 12:15 am

### Post-Module Q#18

The question states: The hydrogen atom has a radius of approximately 0.05 nm. Assume that we know the position of an electron to an accuracy of 1 % of the hydrogen radius, calculate the uncertainty in the speed of the electron using the Heisenberg uncertainty principle.

I calculated first delta x which is 0.001. Then I used the equation: delta v >= h/(m delta x 4pi), but I still couldn't get the correct answer.

Rebecca Park
Posts: 30
Joined: Fri Sep 28, 2018 12:17 am

### Re: Post-Module Q#18

The radius of the atom represents 1/2 of the uncertainty of the position of the electron, the diameter equaling the entire uncertainty. the size of the atom represents the uncertainty in position. You can use this uncertainty, as well as the mass of an electron and the constant h/4pi to calculate delta-v, or the uncertainty in the electron's speed.

Jessica Dharmawan 1G
Posts: 32
Joined: Fri Sep 28, 2018 12:15 am

### Re: Post-Module Q#18

Rebecca Park wrote:The radius of the atom represents 1/2 of the uncertainty of the position of the electron, the diameter equaling the entire uncertainty. the size of the atom represents the uncertainty in position. You can use this uncertainty, as well as the mass of an electron and the constant h/4pi to calculate delta-v, or the uncertainty in the electron's speed.

What do I do with the information stating "Assume that we know the position of an electron to an accuracy of 1 % of the hydrogen radius"?

Laura Gong 3H
Posts: 89
Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 1 time

### Re: Post-Module Q#18

delta X (uncertainty in position) would be 1% times the radius of the atom multiplied by two (which would give you the diameter of the atom).