Chapter 39 - Particles As Waves

Question 1

De Broglie wavelength of an electron:

Answer 1

Lambda = h/p = h/(SQRT(2meV))

Question 2

The maximum momentum transfer to the alpha particle is:

Answer 2

2mv

Question 3

Relationship between impact parameter b and the scattering angle theta

Answer 3

b impact parameter is small
r is small
Coulomb force is large
Theta can be large and the particle can be repelled backwards

Question 4

b=

Answer 4

Z1Z2e^2/(8pi epsilon Ek) * cot (theta/2)

Question 5

Fraction of incident particle scattered:

Answer 5

Target area exposed by scatterers/ total target area

Question 6

Force of attraction on the electron by the nucleus:

Answer 6

F = 1/4pi*epsilon * e^2/r^2 = mv^2/r

Question 7

Total energy:

Answer 7

Ek + V = -e^2/(8piepsilonr)

Question 8

Bohrs Assumptions

Answer 8

Orbiting electrons do not radiate energy.
Classical laws of physics do not apply.
The angular momentum of the nth state is the principle quantum number.

Question 9

What is A0

Answer 9

The Bohr radius
Radius of the hydrogen atom in its ground state.

a0= (4piepsilonh^2)/me^2

Question 10

r_n =

Answer 10

n^2*a0

Question 11

Angular momentum

Answer 11

L=mvr=nN