1. A photon with a wavelength of 2
A photon with a wavelength of 2.29 × 10–7 meter strikes a mercury atom in the ground state.
Calculate the energy, in joules, of this photon. [Show all work, including the equation and substitution with units.] [2] Determine the energy, in electronvolts, of this photon. [1] Based on your answer to the previous question, state if this photon can be absorbed by the mercury atom. Explain your answer. [1]

2. THE FUNDAMENTAL PARTICLES OF ALL MATTER
THE STANDARD MODEL
THE FUNDAMENTAL PARTICLES OF ALL MATTER

3. BASIC DEFINITIONS
FUNDAMENTAL: Most basic unit; particle which cannot be subdivided any further
we now think that protons and neutrons can be broken down even further…protons and neutrons are not fundamental

4. SO WHAT ARE THE FUNDAMENTAL PARTICLES?
6 QUARKS
6 ANTIQUARKS
6 LEPTONS
6 ANTILEPTONS
FORCE CARRIER PARTICLES

5. BARYONS Made up of 3 quarks
Are examples of Hadrons
There are 6 types of quarks
quarks have fractions of electron charge: (1/3)e, +(2/3)e
have interesting names…see right

6. EXAMPLE OF BARYONS
Two common examples of Baryons are the proton and the neutron (remember, must contain 3 quarks)
The Proton: (Has a charge of +1)
so could contain:
u,u,d = (+2/3)e+(+2/3)e+(-1/3)e=+1e
The Neutron (Has a charge of 0)
d,d,u = (-1/3)e+(-1/3)e+(2/3)e = 0e

7. EVERY PARTICLE HAS AN ANTIPARTICLE
An antiparticle has the same mass as its particle, just a charge that is opposite
Examples:
proton particle has an antiparticle called the antiproton
What are the fundamental particles that make up antiparticles?
Remember they are still baryons, so they must still contain 3 quarks (see previous example)

8. ANTIPARTICLE EXAMPLE Previous example: Antiparticle Example:
The Proton: (Has a charge of +1e)
so could contain:
u,u,d = (+2/3)e+(+2/3)e+(-1/3)e=+1e
Antiparticle Example:
The Antiproton: (Has a charge of -1e)
so could contain: antiup, antiup, antidown OR

9. ANTIPARTICLE EXAMPLE CONTINUED note the bar over the quark signifies antiquark…. meaning same mass , but opposite charge

10. EVIDENCE OF ANTIMATTER
PAIR PRODUCTION
A Photon can spontaneously turn into a particle & an antiparticle
cloud chamber paths shows 2 particles emerging as if from nowhere, deflecting in opposite directions in a magnetic field
PAIR ANNIHILATION
When a particle and an antiparticle meet they disappear being replaced by a photon

11. Pair Production - Particle Annihilation & E = mc2
Find the mass of each particle produced when a x J photon disappears
ANSWER:
1.67 X 10-27kg
Find the energy of the photon produced by the annihilation of an electron and anti-electron particle pair:
ANSWER:
1.64 x 10-13J

12. MESONS Contain 1 quark & 1 antiquark
Are another example of a hadron
Are very unstable
(meaning it falls apart easily and quickly)
Examples:
A Pion (+)….which acts as a force carrier
contains an up quark and a down antiquark
An Antipion (-)
this is an example of an antiparticle of a meson
the antipion contains a down quark and an up antiquark

13. LEPTONS (the other type of matter)
They are fundamental particles
they either have a whole number of charge or none at all
most common example of a charged lepton: “Electron”
Muon and tau have more mass than the electron
most common example of an uncharged lepton: “Neutrinos”
very little mass
very hard to find
three types named for their corresponding charged lepton

14. LEPTONS HAVE ANTIPARTICLES TOO
ANTILEPTON EXAMPLE:
POSITRON
Same mass as an electron, but opposite charge

15. HEAVY LEPTONS ARE VERY UNCOMMON
This is because the meson and tau leptons decay very quickly into lighter leptons
LEPTONS DECAY INTO THE FOLLOWING:
its corresponding neutrino + quark & antiquark OR
b)lepton & antineutrino

16. EXAMPLE OF LEPTON DECAY
QUESTION: What does a muon decay into?
1 POSSIBILITY:
Its corresponding neutrino = muon neutrino
A new lighter lepton = an electron
The lighter lepton’s antineutrino = an electron antineutrino

17. FORCE CARRIER PARTICLES
A force is created by an exchange of particles between matter
The particles exchanged depend on the force. All natural forces are listed below from strongest to weakest
Strong Nuclear Force (Strongest)
Electromagnetic Force
Weak Nuclear Force
Gravity (Weakest)

18. THE STRONG FORCE EXCHANGE PARTICLE = GLUONS
mass = 0.1GeV/c2
Force which keeps nucleus together
Strong over short ranges

19. THE ELECTROMAGNETIC FORCE
EXCHANGE PARTICLE = PHOTON
Examples: Coulomb Force, magnetic force
Force is attractive or repulsive

20. THE WEAK INTERACTION FORCE
EXCHANGE PARTICLES = BOSONS (W AND Z)
Involved in nuclear decay, fusion of the sun, conversion of neutrons to protons in the nuclei

21. GRAVITY EXCHANGE PARTICLE = GRAVITON (not yet detected)
Always attractive
Very weak