nuclear

Question 1

what was observed in the Rutherford alpha scattering experiment

Answer 1

most of the alpha particles passed straight through the foil
and very few particles were deflected by angles larger than 90 degrees

Question 2

what did most of the alpha particles passing through the foil indicate

Answer 2

nucleus is mostly empty space with most of the mass concentrated in a small region

Question 3

what does the angles being reflected more than 90 degrees indicate

Answer 3

the nucleus has a positive charge which was repelling the alpha particles

Question 5

how do estimate the size of the nucleus

Answer 5

equate the initial kinetic energy of the alpha particle to the electrical potential energy

r=Qq/4πƐ0(KE)

Question 6

what is the equation for electrical potential energy

Answer 6

Qq/4πƐ0r

Question 7

what does A. stand for next to chemical element

Answer 7

the nucleon number number of protons and nuetrons

Question 8

what does z stand for

Answer 8

the proton number the number of protons

Question 9

what is the equation for nuclear size

Answer 9

R = r0A^1/3
where R is the radius
r0 is a constant
and A is A is the nucleon number

Question 10

how do you work out the density of the nucleus

Answer 10

d=m/v
d=m/(4/3)πR^3
d=m/(4/3)π(r0A^1/3)^3
d=m/(4/3)π(r0A)

Question 11

why is the nuclear density independent of the nucleon number

Answer 11

mass =kA
and so A cancels out in d=kA/(4/3)π(r0A)

Question 12

what is true about the strong nuclear force

Answer 12

acts on all nucleons
short ranged force
attractive up to 3fm
and repulsive believe 0.3 fm

Question 13

what does every particle have

Answer 13

every particle has a corresponding antiparticle

Question 14

what is true about antiparticles and corresponding particles

Answer 14

have the same rest mass
and opposite charge

Question 15

what does the gravitational force act on

Answer 15

all objects with mass

Question 16

what does the electromagnetic force act on

Answer 16

all particles with charge

Question 17

what is the weak nuclear force responsible for

Answer 17

beta plus and beta minus

Question 18

what force are hadrons affected by

Answer 18

the strong nuclear force

Question 19

what force are leptons not affected by

Answer 19

strong nuclear force

Question 20

what is the activity of a radioactive source

Answer 20

the rate of decay of. radioactive source

Question 21

unit for activity

Answer 21

Bq becquerel

Question 22

equation for activity

Answer 22

A=ΔN/Δt

Question 23

what is the decay constant

Answer 23

probability of decay of a single nucleus

Question 24

what are the units of decay constant

Answer 24

s^-1

Question 25

what is the equation of activity involving the decay constant

Answer 25

A=λN

Question 26

what happens to activity and the number of particles against time

Answer 26

decay exponentially against time

Question 27

write the exponential equations of activity and number of particles

Answer 27

A=A0e^-λt N=N0e^-λt

Question 28

what is Δm equal to

Answer 28

Δm=mfinal - m initial

Question 28

what is Einsteins famous energy equation

Answer 28

E=Δmc²

Question 29

what is binding energy

Answer 29

energy require to completely separate a nucleus into its constituents

Question 30

what is the mass defect

Answer 30

the difference between the mass of a completely separated nucleus and the nucleus itself

Question 31

what is the binding energy per nucleon

Answer 31

minimum energy required to remove a nucleon from the nucleus

Question 32

how do you work out the binding energy per nucleon

Answer 32

use E=Δmc² where m is the mass defect and then divide the energy by the number of nucleons

Question 33

what is nuclear fusion

Answer 33

when two lighter nuclei combine to produce a heavy nucleus

Question 34

what is nuclear fission

Answer 34

when a heavy nucleus splits into two lighter nuclei

Question 35

for the binding energy per nucleon graph against nucleon number what is the most stable element

Answer 35

iron 56

Question 36

for the binding energy per nucleon against nucleon number what is true about elements to the right of iron 56

Answer 36

there's fission taking place

Question 37

for the binding energy per nucleon against nucleon number what is true about elements to the left of iron 56

Answer 37

there's fusion taking place

Question 38

what happens in a induce nuclear fission chain reaction

Answer 38

a single thermal neutron is absorbed by a nucleus creating a heavier unstable nucleus which undergoes fission and its split into two nuclei and more nuetrons

Question 39

what do fuel rods

Answer 39

contain uranium fuel

Question 40

what do control rods

Answer 40

absorb some of the neutrons to condo the rate of the nuclear reaction

Question 41

what does the moderator o

Answer 41

slows down the fast moving neutrons to create thermal neutrons

Question 42

what do you need for nuclear fusion to take place

Answer 42

high temperature and high pressure for the nuclei to overcome the electrostatic repulsion

Question 43

what Is carbon dating used for

Answer 43

used to estimate the age of dead living organisms

Question 44

out of carbon 12 and carbon 14 which is radioactive

Answer 44

carbon 12 stable carbon 14 radioactive

Question 45

how is carbon 14 produced

Answer 45

continuously produced in the atmosphere by cosmic rays

Question 46

what happens once a living organism dies

Answer 46

it stops absorbing carbon and so the carbon 14 continues to decay

Question 46

what is true about the ratio of carbon 12 to carbon 14 in all living things

Answer 46

it is constant

Question 47

what is the half life equation

Answer 47

t(1/2)=ln2/λ

Question 48

what does technetium 99 produce

Answer 48

releases gamma radiation

Question 49

what is technetium 99m used for

Answer 49

medical tracer which is injected into the blood stream absorbed by organs bones and muscles when technetium 99m decays releases gamma radiation gamma radiation travels at the speed of light through bones muscles and organs a gamma camera can detect the technetium

Question 50

what are the advantages of technetium 99m

Answer 50

big enough half life to allow for absorption of organs muscles and bones half life is short enough so overall radiation is low and not harmful