Particles and Waves Flashcards
Key area: The standard model
How many quarks make up a proton or a neutron?
Three
Key area: The standard model
As a particle undergoes beta decay, what is emitted in addition to a beta particle?
A neutrino
Key area: The standard model
How do anti-matter particles compare to matter particles?
Anti-matter particles have the same properties as matter particles but with opposite charge.
Key area: The standard model
What are particles made of a quark/anti-quark pair known as?
Mesons
Key area: The standard model
Protons and neutrons belong to which group of particles?
Baryons
Key area: The standard model
When quarks are combined to make mesons or baryons, what must be true about the resultant charge of these combinations?
The resultant charge must be an integer number.
Key area: The standard model
Which group of particles do electrons and neutrinos belong to?
Leptons
Key area: The standard model
State the four forces associated with the interaction of matter.
- The weak nuclear force
- The strong nuclear force
- Electromagnetism
- Gravitation
Key area: The standard model
The force-mediating particles belong to which group of particles?
Bosons (force-mediating particles are known as ‘gauge bosons’.)
Key area: The standard model
Name the different force-mediating particles.
- Photons
- W & Z bosons
- Gluons
- Gravitons (predicted)
Key area: The standard model
Name the different force-mediating particles in order of strength from highest to lowest.
- Gluons
- Photons
- W & Z bosons
- Gravitons (predicted)
Key area: The standard model
Name the different fermions (matter particles).
- Quarks (6 types)
- Leptons (electron, muon and tau together with their neutrinos)
Key area: Forces on charged particles
What does a charged particle experience in an electric field?
A force
Key area: Forces on charged particles
If an electron is placed half way between two charged parallel plates, which way will the electron move and why?
Towards the positive plate due to attraction between the negatively charged electron and this plate.
Key area: Forces on charged particles
Using the relationship
Ew = QV, define 1V.
1V is where 1J of energy is given to 1C of charge in the circuit.
(Rearrange Ew = QV to V = Ew/Q to help with this)
Key area: Forces on charged particles
Using the relationship
Ew = QV, define 6.2V.
6.2V is where 6.2J of energy is given to each coulomb of charge in the circuit.
(Rearrange Ew = QV to V = Ew/Q to help with this)
Key area: Forces on charged particles
Given the charge on a particle and the potential difference between two plates, how is it possible to calculate the speed of that particle having travelled from one side to the other.
Calculate the work done in moving the charge to one side then use this figure as Ek in Ek = ½mv2.
Key area: Forces on charged particles
What will exist round a current carrying conductor?
A magnetic field.
Key area: Forces on charged particles
When determining the force applied to a current carrying conductor in a magnetic field, is the right or left hand rule applied when considering the flow of negative charge?
Right hand rule.
Key area: Forces on charged particles
Why is more energy required to accelerate a proton than an electron?
The proton has more mass than the electron.
Key area: Forces on charged particles
Explain what particle accelerators are designed to do.
Particle accelerators are used to accelerate charged particles to high speeds to collide these particles against each other.
Once a collision takes place, the results can be analysed by detectors.
Key area: Forces on charged particles
What is the purpose of magnets in a particle accelerator?
Magnets are used to make particles follow a specific path in the particle accelerator and also to ensure that collisions occur.
Key area: Nuclear reactions
During a reaction, the total mass of the reactants is greater than the total mass of the products. Why is this the case?
Mass is lost as energy during the reaction.
Key area: Nuclear reactions
What is the process of splitting large mass atoms to smaller mass atoms known as?
Fission
Key area: Nuclear reactions
What is the process of joining small mass atoms to larger mass atoms known as?
Fusion
Key area: Nuclear reactions
What is the problem with containing a fusion reaction?
Extremely high temperatures make containment challenging.
Key area: Wave particle duality
What effect was shown to support the particulate model of light?
The photoelectric effect.
Key area: Wave particle duality
If two photons, one of green light and one of UV light, are incident on a zinc surface, which will cause photoemission and why?
The UV light as it has higher frequency, therefore greater energy (E = hf)
Key area: Wave particle duality
In the photoelectric effect, what is the threshold frequency (f0)?
The minimum frequency of a photon required to cause photoemission from a material.
Key area: Wave particle duality
In the photoelectric effect, what is the work function (hf0)?
The minimum energy of a photon required to cause photoemission from a material.
Key area: Wave particle duality
If a photon of energy
- 78 x 10-19J is incident on a surface with work function of
- 50 x 10-19J, what happens to the remaining energy?
The remaining energy becomes kinetic energy in the ejected photoelectron.
Key area: Wave particle duality
If the wavelength of a photon is supplied, what must be done to determine the energy of that photon?
Use the general wave equation,
v = f x lambda to find the frequency and then use this frequency in E = hf.
Key area: Forces on charged particles
Describe the electric field lines between two parallel plates.
Key area: Forces on charged particles
Describe the electric field lines around a negative point charge.
Key area: Forces on charged particles
Describe the electric field lines around a positive point charge.
Key area: Forces on charged particles
Describe the electric field lines around a positive and negative point charge placed close to each other.
Key area: Interference and diffraction
What term is given to waves with the same frequency, wavelength, velocity and phase difference?
Coherent
Key area: Interference and diffraction
Describe what happens as the maxima (or minima) of two waves combine in phase.
The two waves will interfere constructively creating a wave of greater amplitude.
Key area: Interference and diffraction
Where two waves of the same velocity and frequency meet half a wavelength out of phase, describe what happens as the peak of one wave and the trough of another combine.
The two waves will interfere destructively where the waves cancel each other out.
Key area: Interference and diffraction
If the path difference to the 3rd order maximum in a double slit experiment is 6cm, what is the wavelength of the wave?
Path difference = n x lambda,
Therefore lambda = 6/3 = 2cm.
Key area: Interference and diffraction
If the path difference to the 0th order minimum in a double slit experiment is 12cm, what is the wavelength of the wave?
Path difference = n x lambda,
Therefore lambda = 12/0.5 = 24cm.
Key area: Interference and diffraction
In the relationship below, what does m represent?
The maximum or minimum where:
1 = 1st maximum, 2 = 2nd maximum etc.
0.5 = 1st minimum (0th order min), 1.5 = 2nd minimum (1st order min) etc.
Key area: Interference and diffraction
In the relationship below, what does d represent?
The slit spacing measured in metres.
Key area: Refraction of light
Define the refractive index of a material.
The ratio of the speed of light in a vacuum to the speed of light in the material.
Key area: Refraction of light
What do all three sections of the following relationship have in common?
They all equate to the refractive index of a material.
Key area: Refraction of light
What happens to the refractive index of light as it changes from the red end to the violet end of the spectrum?
The refractive index increases.
Key area: Refraction of light
In the diagram, list the order of refracted light colours from top to bottom?
Red
Orange
Yellow
Green
Blue
Indigo
Violet
Key area: Refraction of light
In the diagram, where the white light is split by a diffraction grating into the spectra above and below the central maximum, which colour is on the outside of both spectra?
Red
Key area: Refraction of light
Define the term ‘critical angle’.
The angle of incidence at which light passing through a medium changes to totally internally reflected light.
Key area: Spectra
Define ‘irradiance’.
Irradiance is the power per unit area incident on a surface, measured in Wm-2.
Key area: Spectra
Describe what this relationship means.
Irradiance is inversely proportional to the square of the distance from a point source.
Key area: Spectra
What is the name given to lowest energy level in the diagram?
Ground state
Key area: Spectra
What happens when an electron goes beyond the outermost energy level in the diagram?
Ionisation
Key area: Spectra
What happens as an electron falls from an upper energy level to a lower energy level?
A photon of energy equal to the difference between the two energy levels is emitted. (E = hf)
The greater the energy difference, the higher the frequency of this photon.
Key area: Spectra
Name this diagram.
Line emission spectrum.
Key area: Spectra
Explain how the individual lines on this diagram occur.
Each line corresponds to an electron transition within the elements present in a light source.
Each line represents a different energy gap, therefore a different frequency of light.
Key area: Spectra
Name this type of spectrum.
Continuous spectrum
Key area: Spectra
Name this type of spectrum.
Absorption spectrum
Key area: Spectra
Explain the formation of dark lines in this type of spectrum.
Photons of light of particular frequencies are being absorbed by elements present in the atmosphere of a star.
These frequencies are not present in the spectral diagram so they appear as dark lines.
Key area: Refraction of light
Define the term ‘total internal reflection’.
Total internal reflection is where a light ray strikes the boundary of a material (e.g. glass) at an angle larger than the critical angle of that material. All light is reflected within the glass.
