Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physics > Atomic Structure and Radiation > Flashcards

Atomic Structure and Radiation Flashcards

1
Q

what is the charge of a proton

A

+1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the mass of a proton

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the charge of a neutron

A

0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the mass of a neutron

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the charge of an electron

A

-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the mass of an electron

A

1/2000 of a protons mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what was the arrangement of john daltons atom

A

tiny spheres
cannot be divided
everything is made from them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the names of atom discoverers in order

A

john dalton
jj thompson
ernest rutherford
niels bohr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what was jj thompsons atom like

A

plum pudding - positively charged matter spread with electrons buried
discovered the electron
mass is spread throughout the atom
charge is spread throughout the atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is ernest rutherford atom like

A

alpha particles fired at gold nuclei
most of alpha particles passed through = most of the atom is empty space
some alpha particles are deflected through a big angle = nucleus has a large positive charge
only a small number of particles rebound backwards = nucleus of atom is very small

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is neil’s bohrs atom like

A

discovered shells
electrons orbit the nucleus at set distances and with a specific amount of energy
electrons move from one level to another by absorbing and emitting electromagnetic radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the mass number

A

number of protons and neutrons inside the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the atomic number / proton number

A

number of protons in the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is an ion

A

an atom that gets charge by gaining or losing electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

when is a negative ion formed

A

when the number of protons minus the number if electrons is a minus number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when is a positive ion formed

A

when the number of protons minus the number of electrons is positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what happens when an unstable nucleus emits radiation

A

it is said to decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is activity

A

number of decays measured per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is activity measured in and by

A

becquerets , with a geiger counter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when will a nucleus emit radiation

A

you cannot say, it is a random event that happens without anything being done to the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the four types of radiation

A

alpha
beta
gamma
neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the nature of alpha

A

particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is an alpha particle made up of

A

two protons
two neutrons (helium nucleus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is alphas range in air

A

2-3cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is alpha absorbed by
paper
26
what is alphas ionising ability
the most out of the three types
27
what is the nature of beta
particle
28
what is beta made up of
fast moving electrons
29
what is betas range in air
1-2m
30
what is beta absorbed by
o.5cm of aluminium
31
what is betas ionising ability
middle of the three types
32
what is the nature of gamma
wave
33
what is gamma made up of
high energy electromagnetic wave
34
what is gammas range in air
unlimited
35
what is gamma absorbed by
2-3cm of lead or 1-2m of concrete
36
what is gammas ionising ability
least of three types
37
when is a beta particle emitted
when a neutron in a nucleus decays into a proton
38
what happens when gamma radiation is emitted
there is no change to the make up of the nucleus so a new element isn't formed
39
what is radioactive decay (description not definition)
random and spontaneous
40
what are the two half life definitions
the time it takes the number of radioactive nuclei in a sample to decrease by 50% the time it takes the count rate from a radioisotope to decrease by 50%
41
why is radiation dangerous
it is able to knock electrons out of atoms
42
what are the dangers of radioactive substances
can contaminate other materials they come in contact with ionisation can damage or kill cells damage to the genes in a cell can cause mutations and cancer
43
what does irradiate mean
exposed to radiation but does not become radioactive
44
what does contaminate mean
exposed to radiation and becomes radioactive
45
radius of an atom
1 x 10 ^-10
46
how much smaller is the radius of the nucleus of an atom than the radius of the atom
10,000 x smaller
47
where is the mass of the atom concentrated
the nucleus
48
what are isotopes
atoms of the same element but with different masses, which have the same protons but different number of neutrons
49
what happens when electrons move to a higher orbit
the atom has absorbed EM radiation
50
what happens when the electrons fall to a lower orbit
the atoms have emitted EM radiation
51
what happens if an electron gains enough energy
it can leave the atom to form a positive ion
52
what was the problem with the rutherford model?
if rutherford was right, the electrons in the cloud close to the nucleus would get attracted and cause the atom to collapse
53
what causes a nucleus to give out radiation
unstable nuclei
54
why do nuclei give out radiation
to become more stable
55
what is the name of the process where a nucleus gives out radiation to become stable
random process called radioactive decay
56
what is activity
the rate at which a source of unstable nuclei delays
57
what is the rate of nuclei decay measured in
becquerel (Bq)
58
what is count rate?
the number of decays recorded by a detector per second
59
what is half life of an isotope? (both definitions )
the time taken for half the nuclei in a sample to decay time taken for the activity or count rate of a sample to decay by half
60
what cannot be predicted ? ( nuclei decay)
when any one nucleus will decay
61
what is the impact of the half life being constant
it enables the activity of a very large number of nuclei to be predicted during the decay
62
what does a short half life mean
-the source has less risks as it does not remain strongly radioactive - this means initially it is very radioactive but dies down - it presents less of a risk long term
63
what does a long half life mean?
-the source remains weakly radioactive for a long time
64
what is the half life of americium?
432 years
65
what is americium used in
- smoke alarms
66
why is americium used as a smoke alarm
it is an alpha emitter
67
how is americium used in smoke alarms
- it is emitted into the air around the alarm and does not reach far because alpha is weakly penetrating -if smoke reaches the alarm, the amount of alpha particles in the surrounding air drops -this causes the alarm to make a sound
68
why is americium suitable for smoke alarms
it will not need to be replenished weak activity wont be harmful to anyone
69
what is contamination
the unwanted presence of radioactive atoms on other materials
70
what is the hazard of contamination?
the decaying of the contaminated atoms releasing radiation
71
what is irradiation
exposing an object to nuclear radiation but not making it radioactive
72
why are medical items irradiated
to kill bacteria on its surface
73
what is background radiation
weak radiation that can be detected from natural/ external sources
74
which natural sources can background radiation be from?
-cosmic rays -radiation from underground rocks -nuclear fallout -medical rays
75
what can affect the level of background radiation?
occupation and or location
76
what is the measurement of radiation dose
Sieverts (Sv)
77
what is technetium used as?
a medical tracer
78
what features make technetium be used as a medical tracer?
-half life of 6 years -decays into a safe isotope that can be excreted by the body -its injected/swallowed so there is enough time for it to be detected before it decays away and is present for a short enough time to minimise harm from radiation - gamma emitter so can pass through the body tissue without being absorbed
79
how is radiation used in chemotherapy
-gamma emitters are used to emit gamma rays which are directed onto areas of the body with cancer cells , which absorb the energy and die controlling the disease -it is used to control other unwanted tissue -as it is hard to direct , surrounding healthy cells can be irradiated and cause side effects
80
what is nuclear fission?
the splitting of a large and unstable nucleus
81
what is usually needed for nuclear fission to occur
the unstable nucleus must first absorb a neutron
82
what happens when the unstable nuclei absorb a neutron
it splits into two smaller nuclei (equal size) and emits two or three neutrons and gamma rays
83
how is energy released (nuclear fission)
by the fission reaction
84
what happens in the process of nuclear fission
the neutron may collide with another radioactive nucleus this nucleus absorbs the neutron and becomes unstable this nucleus splits releasing another neutron and producing more energy
85
how is nuclear fission a chain reaction
as energy is being released and one split causes another to occur
86
why does a neutron need to be absorbed before it splits
it needs extra energy before it can split and release lots of energy
87
what happens if the chain reaction is not controlled?
it will increase at an exponential rate
88
what is nuclear fusion
when two small nuclei fuse to form a heavier nucleus releasing lots of energy
89
the sum of...
the masses of the two nuclei is more than the mass of the heavier nucleus
90
what happens to some of the mass (nuclear fusion)
converted into energy (released as radiation)
91
what is an example of a natural fusion reactor
the sun
92
what is the benefit of fusion over fission
fusion would be a more efficient way of producing energy compared to fission but there is no design that could accomplish positive net energy on earth

Physics (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions