3.2.1.4 Particles and Radiation: Particle interactions

Question 1

What are all forces caused by?

Answer 1

Particle exchange

Question 2

What are exchange particles?

Answer 2

How forces act between two particles. They are virtual particles

Question 3

What is a virtual particle?

Answer 3

A particle that only exists for a very short amount of time - long enough to transfer energy, momentum and other properties between particles in the interaction.

Question 4

What causes electrostatic repulsion?

Answer 4

The exchange of virtual photons

Question 5

What are exchange particles called for the four fundamental forces?

Answer 5

Gauge boson

Question 6

What is the gauge boson for strong interaction?

Answer 6

Pions, pi+, pi-, and pi0

Question 7

What particles are affected by strong interaction?

Answer 7

Hadrons only

Question 8

What is the gauge boson for electromagnetic interaction?

Answer 8

Virtual photon (symbol is gamma)W

Question 9

What particles are affected by em interaction?

Answer 9

Charged particles only

Question 10

What is the gauge boson for weak interaction?

Answer 10

W+, W- bosons

Question 11

What type of particles are affected by weak interaction?

Answer 11

All types

Question 12

What determines the range of the force?

Answer 12

The size of the exchange particle - heavier exchange particles have a shorter range.

Question 13

Why does the em force have infinite range?

Answer 13

The photon has zero mass

Question 14

Describe beta-minus decay

Answer 14

n -> p + e- + electron antineutrino

Question 15

Describe beta-plus decay

Answer 15

p -> n+ e+ + electron neutrino

Question 16

Describe electron capture

Answer 16

p + e- -> n + electron neutrino

Question 17

What is electron capture?

Answer 17

Where proton-rich nuclei ‘capture’ an electron from inside the atom and change into a neutron.

Question 18

What is the exchange particle for electron capture?

Answer 18

W+ boson

Question 19

What is the exchange particle for beta-minus decay?

Answer 19

W- boson

Question 20

What is the exchange particle for beta-plus decay?

Answer 20

W+ boson

Question 20

What is an electron-proton collision?

Answer 20

Where an electron collides at high speed with a proton - the electron is the particle that’s acting because it’s being fired at the proton, so the boson comes from the electron

Question 21

Describe electron-proton collision

Answer 21

p + e- -> n + electron neutrino

Question 22

What is the exchange particle for electron-proton collisions?

Answer 22

W- boson

Question 23

What is the exchange particle for electro magnetic repulsion?

Answer 23

Virtual photon (gamma)

Question 24

What is electromagnetic repulsion?

Answer 24

When particles with equal charge get close to each other, they repel.