Flashcards in Radiation Deck (41)
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1
How does a PET scan work?
Patient is injected with a radioactive tracer which emits positrons. Positrons collide with electrons and annihilate. We can then detect the gamma rays being emitted and pinpoint where the positron was released.
2
How is the location of the gamma radiation found?
A gamma camera
3
What is internal radiotherapy?
When a source of beta radiation is inserted into the body near a tumour
4
What is external radiotherapy?
Where several lower energy beams are directed at the tumour to reduce damage to surrounding cells.
5
What is irradiation?
When you are exposed to a nearby radioactive source but when you move away it stops.
6
What is contamination?
When radioactive particles get under the skin or in the body. The person will be exposed until the unstable nuclei have decayed.
7
What does ionising radiation do?
Removes the electrons from DNA which causes mutation
8
Who came up with the plum pudding model?
J.J Thompson
9
Who shot atoms through a gold sheet?
Rutherford
10
Most of an atom is...
Empty space
11
Who came up with the idea of the electron orbit?
Neils Bohr
12
Protons have a relative mass of...
1
13
Protons have a charge of...
+1
14
Neutrons have a relative mass of...
1
15
Neutrons have a relative charge of...
0
16
Electrons have a relative mass of...
0
17
Electrons have a relative charge of...
-1
18
What happens if an atom loses an electron?
It becomes a positive ion
19
What happens if an atom gains an electron?
It becomes a negative ion
20
When is EM energy or visible light released?
When electrons move between energy levels
21
How does an electron become 'free'?
It can absorb enough radiation that with enough energy it can move so far it leaves the atom
22
What are positive and negative ions?
Positive- more protons
Negative- more electrons
23
What number is at the top?
Mass number
24
What number is at the bottom?
Atomic number
25
Relative charge of a positron?
+1
26
Relative mass of a positron?
0
27
Electrons take in energy to...
Jump up shells
28
Electrons give out energy to...
Jump down the shells
29
When the electrons in the atom lose energy they...
Move to a lower electron shell
30
