6.4 - Particles - Nuclear and Particle Physics

Question 1

What are the four fundamental forces

Answer 1

Strong nuclear
Electromagnetic
Weak nuclear
Gravitational

Question 2

What does strong nuclear force do

Answer 2

It is experienced by nucleons

Question 3

What does electromagnetic force do

Answer 3

Experienced by static and moving charged particles

Question 4

What does weak nuclear force do

Answer 4

Responsible for beta decay

Question 5

What does gravitational force do

Answer 5

Experienced by all particles with mass

Question 6

What is the mass energy equivalence equation

Answer 6

E = mc^2

Question 7

What is the most stable isotope

Answer 7

Iron (Fe-56)

Question 8

What is the correct notation for elements

Answer 8

A = Nucleon number
X = Element
Z = Proton number

Question 9

What is the range of strong nuclear force

Answer 9

Repulsive up to 0.5fm and attractive up to 3fm

Question 10

What is an antiparticle

Answer 10

Every particle has a corresponding antiparticle with the same mass but opposite charge

Question 11

What is the antiparticle for an electron

Answer 11

Positron

Question 12

What is a hadron

Answer 12

A type of particle which is affected by the strong nuclear force

Question 13

What are the classes of hadrons

Answer 13

Baryon (3 quarks)
Mesons (2 quarks)

Question 14

What is an example of baryons

Answer 14

Protons and neutrons

Question 15

What are leptons

Answer 15

Fundamental particles which are not subject to strong nuclear force (but do via weak nuclear force)

Question 16

What are examples of leptons

Answer 16

Electrons and neutrinos

Question 17

What are the types of quarks

Answer 17

Up (u)
Down (d)
Strange (s)
and all have anti particles

Question 18

What are the charges of up down and strange

Answer 18

Up = +2/3e
Down = -1/3e
Strange = -1/3e

Question 19

What is the quark composition for protons and neutrons

Answer 19

Proton (uud)
Neutron (udd)

Question 20

Which quark decays in beta minus decay

Answer 20

A down quark turns into an up quark

Question 21

What is the activity of a source

Answer 21

The number of radioactive decays per second (measured in Becquerels, Bq)

Question 22

What is the Activity equation

Answer 22

A = λN
A = Activity
λ = Decay constant
N = number of radioactive nuclei

Question 23

What is the half life of an isotope

Answer 23

The average time taken for the activity of a sample to halve

Question 24

What is the equation with activity of a sample

Answer 24

A = Aoe^–λt

Question 25

What happens when a particle and antiparticle meet

Answer 25

Annihilation Which releases 2 gamma rays 2 waves are released in order to conserve momentum Mass of the particles will transform into the energy equivalent

Question 26

What is mass defect

Answer 26

The difference between the total mass of all the nucleons separately compared to the mass of nucleus

Question 27

What is binding energy

Answer 27

The energy required to separate a nucleus into its parts

Question 28

What is nuclear fission

Answer 28

Where an unstable nucleus splits into 2 smaller nuclei The binding energy per nucleon increases when fission occurs therefore the overall process releases energy

Question 29

What is fusion

Answer 29

When 2 small nuclei fuse together to create a larger nuclei The new nucleus has a larger binding energy per nucleon than the old nuclei therefore energy is released in this process

Question 30

Does fusion or fission release more energy

Answer 30

Fusion releases a lot more

Question 31

Why is it difficult for fusion to occur on earth

Answer 31

The repulsive force between the 2 positive need to be overcame so heat is created and there is no material which can withstand it and be cost effective

Question 32

How is fission used in reactors

Answer 32

Rods of uranium absorb neutrons and become unstable and then split into 2 daughter nuclei releasing 2 or 3 more neutrons then go on to be reabsorbed by another uranium-235

Question 33

What is the purpose of a moderator (water)

Answer 33

Slow down the neutrons so they travel slow enough to be absorbed They do this through elastic collisions

Question 34

Why are control rods useful

Answer 34

They stop the chain reaction from being out of control They absorb neutrons so that only 1 of the neutrons released in each reaction can go on to be absorbed by another uranium If not the reactor would overheat

Question 35

What is a chain reaction

Answer 35

When 1 neutron from each decays goes on to cause another decay so the amount of energy remains constant

Question 36

How is nuclear waste (used fuel rods) disposed of

Answer 36

First stored in cooling ponds Then put in a sealed container and stored deep underground or underwater

Question 37

What is an environmental benefit and risk of nuclear power

Answer 37

Benefit - No release of greenhouse has, no fossil fuels consumed Risk - leak or escape of material can be catastrophic