Particle Physics

Question 1

1. Charge on one proton
2. Charge on one neutron

Answer 1

1. Proton is uud so
   ⅔e + ⅔e - ⅓e =e
2. Neutron is udd so
   ⅔e -⅓e -⅓e = 0

Question 2

Proton and nucleon of
A. β‐
Β. β+

Answer 2

A. β‐
n = 90
p = 39

Β. β+
n = 64
p = 28

Question 3

State the name of the force responsible for β decay

Answer 3

Weak nuclear force

Question 4

State the names of the leptons produced in each of the decay processes.
A. β‐decay
Β. β+ decay

Answer 4

A. β‐decay
Electron and electron antineutrino

Β. β+ decay
Positron and electron neutrino

Question 5

Use the quark composition of the neutron to show that the neutron has no charge.

Answer 5

Quark structure is udd
Up down down
Charge = +⅔e - ⅓e - ⅓e = 0

Question 6

Charge and mass of proton

Answer 6

Charge +1.6 x 10^-19 C
Mass 1.67 x 10^-27 kg

Question 7

Charge and mass of β‐

Answer 7

Charge - 1.6 x 10^-19
Mass 9.11 x 10^-31

Question 8

Charge and mass of antineutrino

Answer 8

Charge : 0
Mass : v. Small ~~ 0 kg

Question 9

Do all β- particles have the same velocity?

Answer 9

No they have a range of different velocities

Question 10

Convert R eV to joules

Answer 10

= R × 1.6 × 10^-19 J