Particles and Waves Flashcards
What evidence is there for antimatter?
Positrons discovered ocurring naturally in cosmic rays.
What is the Standard Model?
The Standard Model explains how the basic building blocks of matter interact, governed by four fundamental forces.
What is a fundamental particle?
A fundamental particle is one that cannot be broken down into any sub particles.
What is a Fermion?
It is a matter particle.
What are the two types of Fermions?
Quark
and
Lepton
What are the names of the 6 types of Quarks?
- Up
- Down
- Charm
- Strange
- Top
- Bottom
What are the names of the 6 types of Leptons?
- Electron
- Electron neutrino
- Muon
- Muon neutrino
- Tau
- Tau Neutrino
How does an antimatter particle compare with a matter particle?
Antimatter particle has similar properties to the matter particle but equal and opposite charge.
What is meant by a Hadron?
Particles made from quarks
What is meant by a Baryon?
Baryons are made from 3 quarks
What is meant by a Meson?
Mesons are made from 2 quarks.
They always consist of a quark and an antiquark pair.
Give an example of a Baryon.
Proton
Neutron
What is a Boson?
Bosons are force carrying particles.
Name the four Bosons.
- Photons
- W and Z Bosons
- Gluons
- Gravitons
What force is carried by a photon?
Electromagnetic Force
What force is carried by W and Z bosons?
Weak force
What force is carried by a Gluon?
Strong force
What force is carried by a Graviton?
Gravity force
A proton is made up of two up quarks and a down quark. The up quarks are both positively charged. Why does the proton not get torn apart?
Gluons carry the strong force to hold the quarks together. This strong force is greater than the force of repulsion between the particles.
What is beta (minus) decay?
Beta (minus) decay is when a neutron decays into a proton releasing an electron and an antineutrino.
What did beta decay provide the first evidence for?
The existence of neutrinos.
Why were neutrinos suggested as an extra particle produced as a result of beta decay?
When beta decay occurs momentum and energy should be conserved. This was not happening if only the proton and beta particle were considered. There had to be another particle that carried the rest of the energy away.
In physics what is meant by a field?
It is the region where an object experiences a force.
What is the definition for electric field strength?
The electric force per unit charge acting at a point in the field.
What is the definition for a potential difference of 1 Volt?
There is a potential difference of 1 Volt between two points if I joule of energy is required to move 1 coulomb of charge between the two points.
What will a stationary charge create?
An electric field
What will a moving charge create?
- An electric field
- Magnetic field
What will a moving charge experience in a magnetic field?
A force
What are the fingers representing in the right hand rule?
- First Finger - Field (Magnetic field)
- SeCond finger - Current
- THumb - Thrust (Movement)
What represents a magnetic field coming ‘out of the page’?
A dot
What represents a magnetic field going ‘into the page’?
A cross
Explain how a particle accelerator works.
- Acceleration of charged particles - use an electric field which causes particles to experience a force and accelerates them.
- Deflection of charged particles - magnetic fields are used to chage the direction of the moving charged particles.
- Collision of charged particles - against a fixed target or between two beams of particles.
Does a particle accelerator use a.c. or d.c. to create the electric field?
Explain why.
a.c.
This is because the electric field must change direction every time a particle completes a half circle (Dee) to keep the accelerating potential in the correct direction for the particles motion.
What information do you get from a chemical symbol, such as the one shown below?
Top number = Mass Number = number of protons and neutrons in the nucleus.
Bottom Number = Atomic Number = number of protons in the nucleus.
The letters are the chemical symbol which can be found on the periodic table.
If an unstable nucleus undergoes alpha decay what is given out and what is the effect on the mass number and the atomic number?
An alpha particle is a helium nucleus.
Mass Number - This means that the product mass number + the mass number of a helium nucleus = mass number of the original unstable nucleus.
Atomic Number - This means that the product atomic number + the atomic number of a helium nucleus = atomic number of the original unstable nucleus.
If an unstable nucleus undergoes beta decay what is given out and what is the effect on the mass number and the atomic number?
An electron from the nucleus is given out along with an antineutrino.
The mass number of the product remains the same and the atomic number increases by one.
What is meant by fission?
Fission is when a nucleus of a large mass number splits into two or more nuclei of smaller mass numbers.
What is meant by fusion?
Fusion is when two small mass number nuclei combine to form a nucleus of a larger mass number.