particles

Question 1

in the basic model of the atom, what are the constituents of the atom and where are they located?

Answer 1

protons, neutrons and electrons.
protons and electrons are located in the nucleus, and electrons orbit the nucleus in discrete energy levels

Question 2

what are the relative charges of protons, neutrons and electrons?

Answer 2

proton: +1
neutron: 0
electron: -1

Question 3

what is the specific charge of a particle?

Answer 3

the charge per unit mass of the molecule.

Question 4

what is proton/atomic number and what is its symbol?

Answer 4

the number of protons in the nucleus. its symbol is Z.

Question 5

what is the mass/nucleon number and what is its symbol

Answer 5

the total number of nucleons in the nucleus (the total number of protons and neutrons). symbol is A.

Question 6

what is an isotope?

Answer 6

atoms with the same atomic number/same number of protons but a different mass number / different number of neutrons

Question 7

what is an alpha particle?

Answer 7

a helium nucleus. consists of 2 protons and 2 neutrons.

Question 8

what are the different types of nuclear decay?

Answer 8

alpha, beta-, beta+, electron capture

Question 9

what is beta- decay?

Answer 9

a neutron decays, forming a proton, electron and antielectron neutrino

Question 10

what is beta+ decay?

Answer 10

proton breaks down into a proton, a positron and an electron neutrino

Question 11

what is electron capture?

Answer 11

electron and proton combine to produce a neutrino and neutron.

Question 12

what is gamma radiation?

Answer 12

this doesn’t involve any particles being emitted from the nucleus, instead a high energy photon is emitted.

Question 13

what does the existence of neutrinos explain?

Answer 13

the variable kinetic energies of beta particles after they’ve been emitted, and ensures lepton conservation rules are obeyed

Question 14

why does the variable kinetic energies of beta particles emitted from the same source pose an issue?

Answer 14

would mean conservation of energy was not being conserved, as they should all have the same energy. the existence of the neutrino explains that this missing energy is carried away by the (anti) electron neutrinos.

Question 15

what is the range of the strong nuclear force

Answer 15

attractive between 0.5-3 fm

Question 16

what is the exchange particle for the strong nuclear force?

Answer 16

the gluon

Question 17

why is there a need for the strong nuclear force?

Answer 17

protons are positive. like charges repel. an attractive force is needed to keep the nucleus together, otherwise the electrostatic repulsion of the protons would mean the nucleus would fall apart.

Question 18

how was the first positron detected?

Answer 18

in a cloud chamber detector, a particle was observed that has electron like properties but curved in the opposite direction to an electron, so much have the opposite charge.

Question 19

what is an antiparticle?

Answer 19

particles and antiparticles have identical masses, but all other properties (e.g. lepton number, charge and spin) are opposite.

Question 20

what happens when a particle and its antiparticle meet?

Answer 20

they annihilate

Question 21

what is annihilation?

Answer 21

when a particle and antiparticle meet, they annihilate and their masses are converted into energy and carried away by 2 photons of equal energy travelling in opposite directions.

Question 22

what is pair production?

Answer 22

when a particle-antiparticle pair are produced from energy.
it always obeys quark, lepton and charge conservation rules

Question 23

what do all baryons decay into?

Answer 23

protons

Question 24

what do all muons and taus decay into?

Answer 24

electrons

Question 25

if a particle interaction involves leptons, what fundamental force must be involved?

Answer 25

weak nuclear force is responsible for all decays of leptons, and all interactions where leptons are produced.

Question 26

which fundamental force do leptons not experience?

Answer 26

leptons cant experience the string nuclear force.

Question 27

what are the 2 types of hadrons?

Answer 27

baryons and mesons

Question 28

which of the fundamental forces can hardons experience?

Answer 28

they can experience all 4

Question 29

what are the 4 fundamental forces?

Answer 29

electromagnetic force gravity weak nuclear force strong nuclear force

Question 30

what is the quark structure of a baryon?

Answer 30

3 quarks or 3 antiquarks

Question 31

what is the quark structure of a meson?

Answer 31

a quark and an antiquark.

Question 32

what types of particles does gravity interact with?

Answer 32

all objects with mass

Question 33

what types of particles does the electromagnetic force interact with?

Answer 33

all objects with charge

Question 34

what types of particles does the strong force interact with?

Answer 34

quarks (baryons and mesons)

Question 35

what types of particles does the weak force interact with?

Answer 35

quarks (baryons and mesons) and leptons

Question 36

what is the exchange particle of the electromagnetic force?

Answer 36

the virtual photon

Question 37

what is the exchange particle of the strong force?

Answer 37

the gluon

Question 38

what is the exchange particle of the weak force?

Answer 38

W+, W- and Z0 bosons

Question 39

what is an exchange particle?

Answer 39

they're force carriers. in order for a fundamental force to exert a force from one particle to another it must exchange some other force carrying particle with the other particle. aka gauge bosons

Question 40

what is a fundamental force?

Answer 40

forces that cannot be explained in terms of other forces.

Question 41

what is the quark structure of a proton?

Answer 41

duu

Question 42

what is the quark structure of a neutron?

Answer 42

ddu

Question 43

what must be conserved in all particle interactions?

Answer 43

energy momentum charge lepton number baryon number

Question 44

when is strangeness conserved/not conserved?

Answer 44

strangeness can change by +/- 1 in weak interactions

Question 45

what are the rules for quark conservation?

Answer 45

in the strong interaction, the number of each type of quark must be conserved in weak interactions, the total number of quarks must be conserved, but the flavours of the quarks can change

Question 46

as well as overall lepton number being conserved, what other conservation rules are there for leptons?

Answer 46

total lepton number of each generation of leptons must also be conserved (ie electron leptons, muon leptons and tau leptons individual need to be conserved)

Question 47

what meson can be an exchange particle, and why?

Answer 47

pions can act as exchange particles, as they have very little mass

Question 48

what is the definition of the atomic mass unit?

Answer 48

1/12th the mass of a carbon-12 atom

Question 49

through what interaction are strange particles produced? how many are created?

Answer 49

strong interaction. created in pairs including a strange and anti-strange quark

Question 50

through what interaction do strange particles decay?

Answer 50

weak interaction