P&W Flashcards
What is an order of magnitude?
It is a power of 10
State what is meant by the term “fermion”
A fermion is a matter particle
State what is meant by the term “boson”
A boson is a force mediating particle
Quarks are ______
fermions (i.e. matter particles)
Leptons are ________
fermions (i.e. matter particles)
List the 6 quarks
Up down strange charm top bottom
List the 6 leptons
electron, muon, tau, electron neutrino, muon neutrino, tau neutrino
List the 4 force mediating particles and their associated force
Photon (electromagnetic force), Z & W+- bosons (weak force), gluon (strong force)
Which force is missing from the Standard Model
Gravity
What is the standard model?
A model of fundamental particles and their interactions
What are hadrons made up of?
Hadrons are composite particles made of quarks
Baryons are a type of ________ and they are therefore made-up of ________
hadron, quarks
Mesons are a type of ________ and they are therefore made-up of ________
hadron, quarks
Baryons are made of _______ quarks
3
Mesons are made of…
a quark-antiquark pair
Describe beta decay and how it is evidence for the existence of the neutrino
beta decay is when a neutron turns into a proton, electron and an anti electron neutrino. The mass after beta decay was much smaller than could be accounted for by mass-energy conversion and pointed to the existence of a new particle, the neutrino
State what is meant by “anti-matter”
Every particle in the standard model has a corresponding anti-particle, identical in every way except charge. These particles are called “anti-matter”.
State one piece of evidence for the existence of antimatter.
When matter meets antimatter they annihilate
What do electric field lines show?
They point from positive to negative and show which way a positive test charge would move if it were to be placed in the field
Describe the process of drawing electric field lines
Imagine placing a small positive charge near the distribution of charges in question. Now imagine and draw which way it would move. Repeat this for evenly-spaced locations around the distribution
What do charged particles experience in an electric field?
An unbalanced force. They therefore accelerate
Opposite charges _____; like charges _____
Opposite charges attract like charges repel
State the definition of potential difference
Potential difference is a measure of the work done W in moving a charge Q against an electric field i.e. V=W/Q voltage is a measure of the energy per unit charge.
Magnetic field lines point from _____ to ______.
Magnetic field lines point from North to South.
Describe a method to determine the motion of charges particles in a magnetic field
- Point fingers in direction of field. 2. Point thumb in direction of velocity. 3. The deflection direction is given by the backhand direction for positive charges and the forehand direction for negative charges
Describe how a particle accelerator words
In a particle accelerator an electric field is used to change the particle’s speed (SQA word: accelerate) while it is most common to use a magnetic field to change the particle’s direction (SQA word: deflect). High energy collisions produce new particles.
State what is meant by “nuclear fission”
A big nucleus splits into two smaller nuclei, converting some mass to energy in the process
Describe how to tell if nuclear fission is spontaneous or induced
Induced is usually caused by neutron bombardment. Spontaneous has no trigger
Describe induced fission
A nucleus is forced to split by neutron bombardment.
How can you tell from a nuclear equation whether it describes spontaneous or induced fission?
A neutron will be present in the reactants for induced fission but absent for spontaneous fission.
How can you tell from a nuclear equation whether it shows fission or fusion?
If the equation is for fission, a nuclear species with larger mass number will split into two, each with smaller mass numbers. For fusion two lighter atomic species will join to make one heavier one.