Particle physics and radioactivity (C24,25,26)

Question 1

what model was there before the atom model

Answer 1

plum pudding model

Question 2

what were rutherfords observations

Answer 2

most particles go through

some changed angle

Question 3

what did rutherfords experiment imply

Answer 3

very small nucleus, mostly space

Question 4

what is 1 u

Answer 4

1/12 the mass of a carbon 12 atom

1.661.x10^-27

Question 5

what is r nought

Answer 5

1.2fm

Question 6

what is used to write antiparticles

Answer 6

bar over the letter

Question 7

4 fundamental forces

Answer 7

strong
weak
electromagnetic
gravity

Question 8

what is the range of the strong force

Answer 8

femto metre

Question 9

two classes of matter

Answer 9

hadrons and leptons

Question 10

what is a hadron

Answer 10

something affected by the strong force

Question 11

what is a lepton

Answer 11

something not affected by the strong force

Question 12

What are the six quarks

Answer 12

up
down
strange 
charm
top 
bottom

Question 13

What is a baryon

Answer 13

a type of hadron with 3 quarks

Question 14

What is a meson

Answer 14

a type of hadron with 2 quarks

Question 15

What quarks are in a proton

Answer 15

up up down

Question 16

what are the quarks in a neutron

Answer 16

down down up

Question 17

Four types of decay

Answer 17

alpha
beta +
beta -
gamma

Question 18

why does alpha decay occur

Answer 18

nucleaus to heavy

Question 19

why does beta + decay occur

Answer 19

too many protons

Question 20

why does beta - occur

Answer 20

too many neutrons

Question 21

what must be conserved in decay equations

Answer 21

lepton number (postive for regulaur particles and negative for antiparticles)

Question 22

Describe quark transformation of beta minus decay

Answer 22

down quark –> up quark electron and anti electron neutrino

Question 23

Explain how a cloud chamber works

Answer 23

radiation ionises vapour, which condenses leaving tracks

Question 24

how can you differentiate between types of radiation

Answer 24

magnetic field

Question 25

what is emitted with a positron

Answer 25

neutrino

Question 26

what is emitted with an electron

Answer 26

anti neutrino

Question 27

what is a decay chain

Answer 27

the repeated decays of an element into daughter nuclei

Question 28

what is decay

Answer 28

random and spontaneous

Question 29

what is half life

Answer 29

the time taken for half the nuclei in a substance to decay

Question 30

what is the unit of activity

Answer 30

Bequerels Bq, decays per second

Question 31

what can the decay constant lambda be thought of

Answer 31

the decay probability per unit time

Question 32

How can decay be modelled using spreadsheets

Answer 32

can use an iterative formula, and test values

Question 33

How can materials be dated

Answer 33

use half lifes to calculate lambda and use the percentage of already decayed nulcei

Question 34

What must be true about the elements used to date material

Answer 34

must have very long half life

Question 35

What is true to notice mass defect

Answer 35

Need very precise measurements of very small masses

Question 36

Describe annihilation

Answer 36

particle and antiparticle pair meet and turn into energy

Question 37

describe pair production

Answer 37

a photon becomes a particle antiparticle pair

Question 38

What is important about nuclei before and after fusion or fission

Answer 38

different amounts of mass

Question 39

Why is there fusion in elements up to iron

Answer 39

as they produce energy

Question 40

why is their fission from iron up

Answer 40

as fusion loses energy

Question 41

What is induced fission

Answer 41

fission caused by the instability of absorbing another particle

Question 42

What is a thermal neutron

Answer 42

a slow moving neutron used in fission reactors

Question 43

what does the moderator do?

Answer 43

slows fast moving neutrons

Question 44

what is a control rod

Answer 44

absorbs neutrons in reactor