7 - Atomic, nuclear and particle

Question 1

What did Rutherford’s experiment show?

Answer 1

the atom is mostly empty space
the mass of the atom is within the nucleus
deflected beam of particles must have approached positively charged region - the nucleus
volume of nucleus is very small

Question 2

What are electron energy levels?

Answer 2

specific energies electrons in an atom can have

Question 3

What causes an electron to be excited?

Answer 3

absorption of energy

Question 4

What causes an electron to be relaxed?

Answer 4

emission of energy

Question 5

What is the ground state?

Answer 5

13.6eV - the lowest energy level

Question 6

What is the first excited state?

Answer 6

3.4eV

Question 7

What is the second excited state?

Answer 7

1.5eV

Question 8

What is the ionisation level?

Answer 8

0eV - the highest energy level, at which, the electron can escape the atom, forming an ion

Question 9

What is activity?

Answer 9

the number of nuclear disintegrations per second

Question 10

What is activity measured in?

Answer 10

Bequerels, Bq

Question 11

What is alpha decay?

Answer 11

an element decays to produce a different element and an alpha particle, consisting of two protons and two neutrons

Question 12

What is gamma radiation?

Answer 12

an EM wave emitted due to transitions in the nucleus

often accompanies alpha and beta decay

Question 13

What is beta + decay?

Answer 13

a proton decays into a neutron, a positron and a neutrino

Question 14

What is beta - decay?

Answer 14

a neutron decays into a proton, an electron and an anti-neutrino

Question 15

What is beta?

Answer 15

a fast moving electron

Question 16

What is an electron volt?

Answer 16

a unit of energy
KE electron gains by travelling across a pd of 1 volt
1eV = 1.6x10^-19C

Question 17

What is the equation for energy gain?

Answer 17

energy gain = voltage x charge

Question 18

What is half-life?

Answer 18

the time for half the radioactive isotopes to decay

Question 19

What are quanta?

Answer 19

discrete packets of the EM spectrum

measurement of quantity

Question 20

What are photons?

Answer 20

the smallest discrete amount of EM radiation

elementary particle

Question 21

What is the energy carried by quantum?

Answer 21

E = hf
h = Planck's constant 6.63 x 10^-34Js
f = frequency

Question 22

What is an electronvolt?

Answer 22

an alternative unit of energy

the KE electron gains travelling across a pd of 1 volt

Question 23

What is the equation for energy gain?

Answer 23

E = VQ

Question 24

What is strong force?

Answer 24

the force which exists within the nucleus to hold protons and neutrons together

Question 25

What is the mass defect?

Answer 25

the difference between mass of the nucleus and mass of the individual particles

Question 26

What is the binding energy?

Answer 26

the energy needed to separate the nucleus into individual particles

Question 27

How does the binding energy of the particles change after nuclear fission?

Answer 27

heavier elements are split into lighter elements, with lower binding energy per nucleon

Question 28

How does the binding energy of the particles change after nuclear fusion?

Answer 28

lighter nuclei are joined to form a heavier nucleus with higher binding energy per nucleon

Question 29

What are the characteristics of hadrons?

Answer 29

affected by strong force made of quarks relatively heavy

Question 30

What are the characteristics of barions?

Answer 30

hadrons made of three quarks relatively heavy

Question 31

What are the characteristics of mesons?

Answer 31

hadrons intermediate heaviness made of one quark, one anti-quark

Question 32

What are the characteristics of leptons

Answer 32

not affected by strong force indivisible relatively light

Question 33

What is the charge on an up quark?

Answer 33

+2/3

Question 34

What is the charge on a down quark?

Answer 34

-1/3

Question 35

What is the charge on a strange quark?

Answer 35

-1/3

Question 36

What is the charge on an anti-up quark?

Answer 36

-2/3

Question 37

What is the charge on an anti-down quark?

Answer 37

+1/3

Question 38

What is the charge on an anti-strange quark?

Answer 38

+1/3

Question 39

Which quarks is a proton made out of?

Answer 39

u u d

Question 40

Which quarks is a neutron made out of?

Answer 40

u d d

Question 41

Which quarks is a pion+ made out of?

Answer 41

u /d

Question 42

Which quarks is a pion- made out of?

Answer 42

/u d

Question 43

Which quarks is a pion0 made out of?

Answer 43

either u /u or d /d

Question 44

Which quarks is a kaon+ made out of?

Answer 44

u /s

Question 45

Which quarks is a pion- made out of?

Answer 45

s /u

Question 46

Which quarks is a kaon0 made out of?

Answer 46

d /s

Question 47

Which quarks is a /kaon0 made out of?

Answer 47

s /d

Question 48

What is anti-matter

Answer 48

for each matter particle, there is corresponding anti-particle same mass as corresponding particle but opposite charge when a particle and anti-particle meet, they annihilate and produce two photons

Question 49

Which leptons are electrically charged?

Answer 49

electrons, muons and taons

Question 50

Which leptons have zero mass and zero charge?

Answer 50

electron neutrino muon neutrino tau neutrino

Question 51

What are leptons?

Answer 51

elementary particles | not affected by strong force

Question 52

What are the characteristics of strong force?

Answer 52

``` attractive forces between nucleons p-p and n-n repulsive at ranges less than 1fm range doesn't extent beyond a few nm doesn't depend on charge of nucleus readily saturated by surrounding nucleon ```

Question 53

What virtual particle is exchanged in gravitational force?

Answer 53

graviton

Question 54

What virtual particle is exchanged in electostatic force?

Answer 54

photon

Question 55

What virtual particle is exchanged in strong force?

Answer 55

gluon

Question 56

What virtual particle is exchanged in weak force?

Answer 56

W+, W-, W0 bosons

Question 57

What must be conserved for an equation to be possible?

Answer 57

charge, lepton number and baryon number

Question 58

Which force are neutrinos affected by?

Answer 58

weak force

Question 59

Which reactions conserve strangeness?

Answer 59

any involving strong force or weak force

Question 60

What does the x axis of a Feynman diagram represent?

Answer 60

time

Question 61

What does the y axis of a Feynamn diagram represent?

Answer 61

the space dimension

Question 62

What is an electron moving to the right equivalent to?

Answer 62

a positron moving to the left

Question 63

What does a squiggly line represent?

Answer 63

a photon

Question 64

What are the implications of quark confinement?

Answer 64

quarks cannot be directly observed as free particles | must remain bound to other quarks