Nuclear Fusion and Fission (HL Option C.3 & C.7)

Question 1

what is a fusion reaction?

Answer 1

the fusion of hydrogen nuclei

Question 2

what is the main technological issue involved in fusion?

Answer 2

a fusion takes place at a high temperature that it cant be contained

Question 3

where does the sun’s energy come from?

Answer 3

hydrogen nuclei/ protons combine to form the isotope deuterium which then further combines to form helium

Question 4

what is mass defect?

Answer 4

the difference between the mass of the nucleus and the sum of the masses of its individual nucleons

Question 5

what happens to the mass defect? How can it be quantified?

Answer 5

it is released as energy, E=mc^2

Question 6

what is an electron volt

Answer 6

the energy required to move one electron through a pre defined electric field

Question 7

what is binding energy?

Answer 7

the energy required to separate a nucleus into protons and neutrons

Question 8

what is the fusion of deuterium

Answer 8

hydrogen isotope with 1 proton and 1 neutron with tritium (hydrogen isotope with 2 neutrons) to produce helium and a neutron

Question 9

what is the significance of the difference in binding energy per nucleon between helium and the 2 isotopes of hydrogen?

Answer 9

the nucleon are bound much more tightly in a stable helium in the nucleus, so there is a mass defect which is converted into energy

Question 10

what element has the most stable nuclear configuration

Answer 10

iron

Question 11

what is nuclear fission

Answer 11

elements with an atomic number greater than 92 split to form 2 lighter nuclei

Question 12

what process undergoes in nuclear generated power plants

Answer 12

nuclear fission

Question 13

What prevents chain reactions in nuclear fission?

Answer 13

control rods

Question 14

What is critical mass?

Answer 14

the amount of material needed to keep the reaction sustainable such that sufficient neutrons can continue to sustain a chain reaction

Question 15

What is transmutation?

Answer 15

conversion of one element to another by capture or emission of a particle

Question 16

What is an alpha particle? What is the charge? What are the hazards?

Answer 16

A helium nucleus with two protons and two neutrons; +2; limited hazard unless ingested

Question 17

What is a beta particle? What is the charge? What are the hazards?

Answer 17

High speed electron with negligible mass; -1; can burn skin

Question 18

What is a gamma ray? What are the hazards?

Answer 18

high frequency, short wavelength electromagnetic waves, can cause cancer

Question 19

What is a neutron? What is the charge? What are the hazards?

Answer 19

uncharged nuclear particle with mass of 1 atomic mass unit; high penetrative ability, can cause cancer

Question 20

What is a positron? What is its charge?

Answer 20

the antiparticle of an electron, positively charged beta particle

Question 21

What is a proton? What is its charge?

Answer 21

nuclear particle that has a mass of 1 atomic mass unit; +1

Question 22

What is half life?

Answer 22

time it takes for one half of the atoms in a sample to decay

Question 23

What order is nuclear decay?

Answer 23

1st order

Question 24

How is radioactive waste stored? - long term

Answer 24

waste is encased in steel surrounded by an inert gas and covered in concrete

Question 25

How are the composition of stars analyzed?

Answer 25

Absorption Spectra

Question 26

What is the process of enriching Uranium?

Answer 26

diffusion or centrifugation

Question 27

Why must Uranium be enriched?

Answer 27

only U - 235 is fissionable, however most of uranium found naturally is U - 238 so you have to enrich Uranium in order to increase the concentration of U - 235

Question 28

What series of reactions converts uranium (IV) oxide to gaseous uranium hexafluoride?

Answer 28

UO2 + 4HF -> UF4 +2 H2O | UF4 + F2 -> UF6

Question 29

Why is UF6 used more than UO2?

Answer 29

more volatile because of weak intermolecular forces

Question 30

What is the process of diffusion to separate U - 238 and U - 235?

Answer 30

Gaseous UF6 is pumped through a porous membrane, because U - 235 is lighter, it diffuses faster and more easily, this has to be completed various times to ensure the isotopes have been separated

Question 31

What is the process of centrifugation to separate U - 238 and U - 235?

Answer 31

gaseous UF6 is pumped into a centrifuge where the heaviest (U - 238) is pushed to the outside and up and the lighter (U-235) is pushed inside and out the top

Question 32

What is the formula for Graham's Law of Effusion?

Answer 32

(rate of effusion of gas 1) /(rate of effusion of gas 2) = (molar mass of gas 2)^.5 / (molar mass of gas 1)^.5

Question 33

What are the risks associated with nuclear energy?

Answer 33

health risks, military applications,

Question 34

What is the SI unit or ionizing radiation?

Answer 34

seivert