space physcis/ radiation Flashcards
describe the process of nuclear fission
when an unstable nucleus splits into 2+ nuclei, releasing a lot of energy
describe the process of nuclear fusion
2 nuclei join to make one large nucleus, releasing energy
what is needed for nuclear fusion to occur?
Very high temperatures and pressure.
what is needed for nuclear fission to occur?
neutrons (acts as catalyst)
What is used to limit the rate of nuclear fission?
control rods (absorbs neutrons)
what is alpha radiation?
a slow-moving, positively charged particle.
what is beta radiation?
a fast-moving, negatively charged particle
what is Gamma radiation?
electromagnetic radiation that travels at the speed of light
what does alpha radiation consist of?
2 protons and 2 neutrons (2+ charge)
What stops alpha radiation?
air
what stops beta radiation?
thin foil
what stops gamma radiation?
thick lead or concrete
How does alpha radiation change an element’s atomic number and mass number?
+ 4 to top ( mass)
- 2 to bottom ( atomic)
How does beta radiation change an element’s atomic number and mass number?
+0 to top (mass)
+1 to bottom (atomic)
how can gamma rays be used in medicine?
for killing cancer cells
what is a radioisotope?
a radioactive isotope
what is an isotope?
2+ forms of an element that contain the same amount of protons but a different number of neutrons.(different atomic mass)
define irradiation
the proccess where objects are exposed to radiation
define contamination
when radioactive particles get onto other objects
why is alpha radiation harmful in the body but not harmful if outside?
as alpha can enter cells and harm them, however alpha cannot penetrate air or skin if outside of the body
what is radiotherapy?
using radiation to kill unwanted cells
uses gamma rays if external
uses beta rays if internal
what are medical tracers?
inserting isotopes into the body to track the movement of radiation
this can ensure organs are working properly
uses gamma radiation as it is less ionising
compare nuclear fission and fusion
fission- more radioactive waste
fusion - alot more expensive
fission- produces way more energy
