# Homework Help: Uncertainty Principle and minimum kinetic energy

1. Dec 8, 2009

### cwatki14

An atom represents a region about 1.7 10-10 m wide in which an electron is confined. Use the Heisenberg uncertainty principle to estimate the minimum kinetic energy of the electron, expressing your result in electron-volts (eV).

So I got the problem right when I analyzed the atom as a 1 d region. How will this change if it is a 3d region? I found minimum momentum=h/$$\Delta$$x
and then used the equations KE=p^2/2m...

2. Dec 8, 2009

### Redbelly98

Staff Emeritus
Can you write p2 in terms of px, py, and pz?