Microscope

Step 1: Calculate the electron's de Broglie wavelength.
The de Broglie wavelength

%5Clambda

of an electron is given by:

%5Clambda%20%3D%20%5Cfrac%7Bh%7D%7Bp%7D

where

h

is Planck's constant and

p

is the momentum of the electron. The momentum

p

can be related to the kinetic energy

K

of the electron:

K%20%3D%20eV%20%3D%20%5Cfrac%7Bp%5E2%7D%7B2m%7D

where

e

is the electron charge,

V

is the potential difference, and

m

is the mass of the electron. Step 2: Use the known values.
For

V%20%3D%20200%20%5C%2C%20%5Ctext%7BkV%7D

e%20%3D%201.6%20%5Ctimes%2010%5E%7B-19%7D%20%5C%2C%20%5Ctext%7BC%7D

, and

m%20%3D%209.11%20%5Ctimes%2010%5E%7B-31%7D%20%5C%2C%20%5Ctext%7Bkg%7D

, we find the best resolution to be between 2.30 and 3.20 picometers.

Chapter Questions
1 MCQs