exchange particles

Question 1

four forces

Answer 1

• gravity
• electromagnetic force
• weak force/ interaction
• strong (nuclear) force

Question 2

gravity

Answer 2

• acts between all objects which have mass
• always attractive (never repels)
• infinite range (gets less with distance)
• very weak compared with other forces
• dominant force over large scales

Question 3

electromagnetic force

Answer 3

• acts between all objects which have charge
• can be attractive/ repulsive
• infinite range, but over large scales + and - forces cancel out
• the dominant force on an atomic and molecular level

Question 4

strong force

Answer 4

• acts on hadrons only
• enormously strong within nucleus but limited range
• holds nuclei together

Question 5

weak interaction

Answer 5

• responsible for the interactions between hadrons and leptons
• beta decay
• limited range

Question 6

force/ exchange particle

Answer 6

gravity –> graviton
electromagnetic –> virtual photon
strong –> gluon
weak –> W particles

Question 7

electromagnetic force: exchange particle

Answer 7

virtual photon:

• same properties as photons, only exists for short amount of time
• charged particles exchange virtual photons, causing the force between them
  e. g. repulsion of electrons

Question 8

Feynman diagram of repulsion of electrons

Answer 8

[insert Feynman diagram of repulsion of electrons]

Question 9

weak interaction - beta decay: exchange particles

Answer 9

W-particles:

• can be W+ or W-
• high mass
• very short life, so very short range
  e. g. beta- decay

Question 10

Feynman diagram of beta- decay

Answer 10

[insert Feynman diagram of beta- decay]