Particles and quantum ⚛

Question 1

PROTON

Answer 1

Charge = 1.6 x 10^-19
Relative charge = +1
Mass = 1.67 x 10^-27
Relative mass = 1
Specific charge = 9.58 x 10^7

Question 2

NEUTRON

Answer 2

Charge = 0
Relative charge = 0
Mass = 1.67 x 10^-27
Relative mass = 1
Specific charge = 1.76 x 10^11

Question 3

ELECTRON

Answer 3

Charge = -1.6 x 10^-19
Relative charge = -1
Mass = 9.11 x 10^-31
Relative mass = 0.0005
Specific charge = 1.76 x 10^11

Question 4

Strong nuclear force

Answer 4

Attractive up to separations of 3fm
Repulsive below 0.5fm

Question 5

Unstable nuclei

Answer 5

Too many protons, neutrons or both
So SNF can’t keep them stable so the nuclei decay in order to become stable

Question 6

Alpha decay

Answer 6

Occurs in large nuclei
Too many protons and neutrons
• Protons decreases by 2
• Nucleon number decreases by 4

Question 7

Beta minus decay

Answer 7

Too many neutrons
• Proton number decreases by 1
• Nucleon number stays the same

Question 8

Antiparticle

Answer 8

Same rest energy and mass but opposite in all other properties

Question 9

Photon

Answer 9

How electromagnetic waves travel in packets
Transfer energy and have no mass

Question 10

Photon energy

Answer 10

Directly proportional to the frequency of electromagnetic radiation
E = hf = hc/lamda
(h = planck constant 6.63 x 10^-34 Js)

Question 11

Annihilation

Answer 11

Where particle and antiparticle collide and their masses are converted to energy
The combined energy and ke is released as 2 photons moving in opposite directions to conserve momentum

Question 12

Pair production

Answer 12

Where a photon is converted into an equal amount of matter and antimatter
Can only occur when a photon has energy is greater then the total rest energy of both particles
any excess energy is converted into ke of the particles

Question 13

Strong interaction

Answer 13

Exchange particle : Gluon
Range : 3 x 10^-15
Acts on : Hadrons

Question 14

Weak interaction

Answer 14

Exchange particle : W boson (-&+)
Range : 10^18
Acts on : all particles

Question 15

Electromagnetic interaction

Answer 15

Exchange particle : Virtual photon
Range : Infinite
Acts on : Charged particles

Question 16

Gravity interaction

Answer 16

Exchange particle : Graviton (dw)
Range : Infinite
Acts on : Particles with mass

Question 17

Weak nuclear force interactions

Answer 17

Beta decay, electron capture and electron-proton collisions

Question 18

Electron capture

Answer 18

p + e^- —–> n + ve
(W+)

Question 19

Electron-proton collision

Answer 19

p + e^- —–> n + ve
(W-)

Question 20

Beta-plus decay

Answer 20

p —–> n + e^+ + ve
(W+)

Question 21

Beta-minus decay equation

Answer 21

n —–> p + e^- + anti ve
(W-)

Question 22

Hadron vs lepton

Answer 22

Leptons ARE fundamental and DO NOT experience strong interaction
Hadrons are made of quarks and therefore ARE NOT fundamental

Question 23

Hadrons subgenre

Answer 23

Separated into baryons, antibaryons and mesons
Baryons formed of 3 quarks
Antibaryons formed of 3 antiquarks
Mesons formed of a quark and antiquark

Question 24

Meson example

Answer 24

Pion
Kaon

Question 25

Lepton example

Answer 25

Electron muon electron neutrino

Question 26

Baryon examples

Answer 26

Proton neutron

Question 27

Conservations in particle interactions

Answer 27

Baryon number lepton number charge strangeness momentum and energy

Question 28

Strange particles

Answer 28

Produced by strong nuclear interaction but decay by the weak one Kaons (strangeness +1) decay into pions by the weak interaction Strangeness can only change in the weak interaction

Question 29

UP quark

Answer 29

Charge : + 2/3 e Bryon number : + 1/3 Strangeness : 0

Question 30

DOWN quark

Answer 30

Charge : - 1/3 e Bryon number : + 1/3 Strangeness : 0

Question 31

STRANGE quark

Answer 31

Charge : - 1/3 e Bryon number : + 1/3 Strangeness : -1

Question 32

Meson quark combination

Answer 32

1. Pi0 = up anti=up or down anti-down (0) 2. Pi+ = up anti-down (+1) 3. Pi- = anti-up down (-1) 4. Kaon0 = down anti-strange (0) 5. Kaon+ = up anti-strange (+1) 6. Kaon- = anti-up strange (-1)

Question 33

Photoelectric effect

Answer 33

Where photoelectrons are emitted from the surface of a metal after light above a certain frequency is shone on it (threshold frequency)

Question 34

Threshold frequency explanation

Answer 34

EM waves travel in discrete packets therefore a photoelectron is only emitted if the frequency is above the threshold frequency Each electron can absorb a single photon, therefore photoelectrons are only emitted if THF is met Intensity increase = more photoelectrons emitted

Question 35

Work function

Answer 35

minimum energy required for electrons to be emitted from the surface of a metal

Question 36

Stopping potential

Answer 36

Potential difference needed across the metal to stop the photoelectrons with the max KE

Question 37

Photoelectric effect equation

Answer 37

E = hf = work function + Ek

Question 38

Electrons in atoms

Answer 38

Only exist as discrete energy levels Gain energy from collisions with free electrons which causes them to move up energy levels which is known as excitation Or they gain enough energy to be removed from the atom entirely which is known as ionisation

Question 39

When does ionisation occur

Answer 39

If the energy of the free electron is greater than ionisation energy

Question 40

Electron excitation

Answer 40

Will quickly return to original energy level (ground state) and therefore releases the energy it gained in the form of a photon

Question 41

Fluorescent tubes

Answer 41

*High voltage applied across the mercury vapour accelerates fast moving free electrons which collide with mercury atoms *Mercury electrons are excited and move back to ground state, emitting a UV photon *The tube's phosphorus coating absorbs the UV photons and its electrons excite. They then cascade down the energy levels and release visible light photons

Question 42

Electron volt

Answer 42

Energy gained by one electron when passing through a potential difference of 1 volt

Question 43

De Broglie wavelength

Answer 43

lambda = h/mv

Question 44

Photon energy equation

Answer 44

E = hc/lambda

Question 45

Ionising energy

Answer 45

minimum energy required to remove the most loosely bound electron of an isolated gaseous atom, positive ion, or molecule