radiation

Question 1

What is alpha radiation made up of

Answer 1

two protons and two neutrons (a helium nucleus)

Question 2

characteristics of alpha radiation

Answer 2

-strongly ionising
-slow moving
-weakly penetrating (stopped by paper)
-positively charged

Question 3

what is beta minus radiation

Answer 3

a high energy electron

Question 4

what is beta plus radiation

Answer 4

high energy positron

Question 5

beta minus characteristics

Answer 5

-mildly ionising
-fast moving
-stopped by a few mm of aluminium
-negatively charged

Question 6

what is gamma radiation

Answer 6

a form of EM radiation

Question 7

characteristics of gamma radiation

Answer 7

-weakly ionising
-travels at the speed of light
-strongly penetrating (stopped by lead)
-chargeless

Question 8

what is radioactive decay

Answer 8

the decay of a substances nuclei, this decay is completely random and unpredictable

Question 9

what is activity (A)

Answer 9

the number of nuclei that decayer second, measured in Bq

Question 10

what is half life

Answer 10

time it takes for the number of radioactive nuclei to halve

Question 11

what is the decay constant (λ)

Answer 11

probability of a decay occurring in a unit time

Question 12

nuclear fission

Answer 12

splitting of a large nucleus, by absorbing a slow moving neutron, and producing two smaller nuclei, several neutrons and energy

Question 14

thermal neutron

Answer 14

slow moving so can be absorbed

Question 15

spontaneous fission

Answer 15

is rare, a fissile nuclei usually needs to absorb a thermal neutron to induce fission

Question 16

chain reactions

Answer 16

neutrons produced in a reaction go on to induce further fission reactions

Question 17

critical mass

Answer 17

minimum amount of a fissile substance needed to maintain a steady flow of fission reactions

Question 18

roll of control rods

Answer 18

to absorb neutrons to prevent further fission reactions (the further in the rods the more neutrons that can be absorbed)

Question 19

roll of the moderator

Answer 19

slows down neutrons to reach thermal speeds to be absorbed

Question 20

roll of fuel rods

Answer 20

consists of fissile material, each rod contains less than the critical mass in horde for collisions to remain controlled

Question 21

roll of coolants

Answer 21

carries a way thermal energy produced by fissile reactions to generate steam and turn generators for electrical energy

Question 22

how do you cool nuclear waste

Answer 22

cooled in cooling ponds to reduce its temp to safe levels

Question 23

where should high level waste be stored

Answer 23

in thick steel containers underground

Question 24

nuclear fusion

Answer 24

fusing two smaller nuclei to form a single large nuclei and produce large quantities of energy

Question 25

which elements are usually used for fusion

Answer 25

tritium and deuterium

Question 26

conditions for nuclear fusion

Answer 26

-very high temp -very high pressure

Question 27

which produces more energy

Answer 27

fusion

Question 28

what is binding energy

Answer 28

energy required to split up the nucleus into its individual nucleus. it is the energy equivalent to the mass deficit.

Question 29

does a greater binding energy mean a more stable nucleus

Answer 29

yes

Question 30

what is mass defect

Answer 30

the difference between the mass of the nucleus and the mass of its individual components

Question 31

why are high temperatures required for nuclear fusion

Answer 31

to provide kinetic energy so that nuclei have sufficient energy to overcome the repulsive forces

Question 32

why are high pressures required for fusion

Answer 32

so that nuclei can get close enough to maintain collision rate to maintain fusion, close enough to form a strong force