Physics 30 - Unit D Lesson 8-9

What are 2 devices you can use in order to examine particles?

1. Cloud Chamber

2. Bubble Chamber

Cloud Chamber

• dust free air with supersaturated liquid allowing particles to ionize with molecules

• the ionization causes the vapour to condense along the path it’s travelling in

• This will show the path of the particle, and therefore reveal the properties of the particle

Bubble Chamber

• Gas at a low pressure

• The boiling point is smaller due to the pressure being lower

• Ions form by the charged particles moving, and therefore leave a track in the particles path (and therefore showing the properties of the particle

3 things to remember about the Devices Detecting Subatomic Particles

1. lighter particles will always curve more (and therefore have a smaller radius)

2. neutral particles do not leave a track due to the lack of charge

   1. conservation of mass + charge must be followed

Antimatter

A particle that has the opposite charge of a certain antimatter

• For example, a positron is the antimatter of an electron

Annihilating

Matter and antimatter collide with each other and completely convert to energy (mass —> energy)

Pair production

Energy converting to matter and antimatter (energy —> mass)

Quantum Field Theory (and what does it rely on)

Fundamental forces acting between 2 particles at a certain distance

• Relies on mediating particles

Mediating Particles

Virtual particles that carry on of the fundamental forces

Virtual particles

Particles that exist for an extremely short amount of time (I’m talking less than a ms)

How much energy is necessary to probe (examine) matter?

Extremely large amounts of energy are needed in order to probe matter, especially for smaller particles

Particle Accelerator

• uses electromagnetic field in order to propel charged particles

• Takes large amounts of energy in order to get close to the nucleus of the atom (overcome the strong nuclear force holding n and p+)

  • Takes even larger amounts of energy in order to examine protons/neutrons

Leptons + 3 examples + do they interact via the strong nuclear force

Very few small fundamental particles (electron, muon, tauon), do NOT interact via the strong nuclear force

Haudrons + do they interact via the strong nuclear force

a lot of large not fundamental particles that interact via the strong nuclear force

what are haudrons made of?

quarks (Up and down)

Quarks

• make up haudrons

• each one has corresponding antiquark (so like antiup or antidown)

• The energy to split a quark is large enough to make a new one

• Protons + neutrons only contain up + down quarks

Beta Negative decay

When a neutron (udd) converts to a proton (uud)

Beta Positive decay

When a proton (uud) converts to a neutron (udd)

What is matter made of?

12 fundamental particles

• 6 leptons

• 6 quarks (that make up hadrons