Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RadProd > Radioactivity > Flashcards

Radioactivity Flashcards

1
Q

Protons and neutrons are packed tightly in the ______, where
you find most of the atom’s mass.

A

nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • allows protons and neutrons to be attracted to each other.
  • 4x stronger than electric force
  • short-range
A

Strong Nuclear Force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • Chemicals with isotopes in which the arrangement of protons and neutrons is less than ideal.
  • these elements exhibit a degree of nuclear instability
A

Radioactive

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

Isotopes which spontaneously emit radiation

A

Radio-isotopes

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

the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves

A

Radioactive decay

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

Radioactivity is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of ___ or ____

A

particles or electromagnetic waves

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

An unstable _____ releases energy to become more stable

A

nucleus

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

After decaying, ____________“change” into other atoms

A

radioactive atoms

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

Father of Radioactivity

A

Henri Becquerel (1896)

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

In <year>, <name> discovered, almost by accident, that uranium
can blacken a photographic plate, even in the dark.</name></year>

A

Henri Becquerel (1896)

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

In 1903, he shared the Nobel Prize in Physics with ____ and
________ “in recognition of the extraordinary services he
has rendered by his discovery of spontaneous radioactivity”.

A

Pierre and Marie Curie

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

Nobel Prize in Chemistry

A

Marie Curie (1911)

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

They discovered other natural
radioactive elements such as
: Radium and Polonium.

A

Marie and Pierre Curie

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

Marie and Pierre Curie discovered other natural radioactive elements such as

A

Radium and Polonium

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

Radioactive material such as______ first discovered by Henri Becquerel

A

Uranium

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

According to M. Curie, the activity of
* 1g Ra = 1Ci = 3.7 x10^10 decays/s or
DPS
1Bq = ____

A

1 decay/s or DPS

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

5 sources of radioactivity:

A
  • Primordial
  • Cosmogenic
  • Human Produced
  • Naturally Occurring Sources
  • Manmade Sources
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

sources of radio activity

from before the creation of the Earth

A

Primordial

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

Sources of radioactivity

formed as a result of cosmic ray interactions

A

Cosmogenic

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

sources of radioactivity

enhanced or formed due to human
actions (minor amounts compared to natural)

A

Human produced

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

sources of radioactivity

  • Radon from the decay of Uranium and Thorium
  • Potassium -40 – found in minerals and in plants
  • Carbon 14 – Found in Plants and Animal tissue
A

Naturally Occuring Sources

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

sources of radioactivity

  • Medical use of Radioactive Isotopes
  • Certain Consumer products –(e.g. Smoke detectors)
  • Fallout from nuclear testing
  • Emissions from Nuclear Power plants
A

Manmade sources

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

2 Types of radio activity

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

Types of radioactivity

By existence, there are elements here on Earth that
is radioactive (ex. uranium, thorium, radium)

A

Natural Radioactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The first major advance
occurred in 1930’s with
the invention of the
cyclotron by **Ernest
Lawrence **in Berkeley,
California.

A

Artificial Radioactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  • Enrico Fermi in Rome started
    systematically exposing the elements
    in the Periodic Table to beams of
    neutrons.
  • Identified 40 new radio-active species and thus was able to show how neutrons that
    had been slowed down prior to
    interacting with the targets gave
    rise to much higher levels of
    radioactivity
A

Artificial radioactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q
  • identified around 40 new
    radio-active species and thus was
    able to show how neutrons that
    had been slowed down prior to
    interacting with the targets gave
    rise to much higher levels of
    radioactivity.
    *_____in Rome started
    systematically exposing the elements
    in the Periodic Table to beams of
    neutrons.
A

Enrico Fermi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

is the energy that is released as particles or
rays, during radioactive decay.

A

Radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q
  • is the property of an atom that describes
    spontaneous changes in its nucleus that create a different element.
  • These changes usually happen as emissions of **alpha or beta particles and often gamma rays. **
A

Radioactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The rate of emission is referred to as a material’s _____

A

activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Each occurrence of a nucleus throwing off particles or energy is referred to as a ______

A

disintegration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The number of disintegrations per unit time (minutes, seconds, or hours) is called the ____

A

activity of a sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

activity is expressed in ___

A

curies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

1 curie =

A

37 billion dps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

DPS

A

disintegrations per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Units of Activity

A

*Curie (Ci)
*Becquerel (Bq)
*disintegration per second (dps)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

applications for radioactivity

 produced during World War II
in Berlin
 On the back of the tube it was
stated that, ‘radioactive
radiation increases the defense
of teeth and gums… cells are
loaded with new life energy, the
destroying effect of bacteria is
hindered… it gently polishes the
dental enamel and turns it white
and shiny.’

A

Doramad radioactive toothpaste

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

In the U.S, hundreds of thousands of people
began drinking bottled water laced with
radium, as a general elixir known popularly
as ____

A

liquid sunshine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

1952 LIFE magazine wrote
about the beneficial effects of inhaling
__________in deep mines.

A

radioactive radon gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

1953, a company in Denver was
promoting a radium-based _________

A

contraceptive
jelly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Atoms found in nature are either ____ or____

A

stable or unstable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

An atom is _____ if the forces among the
particles that makeup the nucleus are balanced.

A

stable

43
Q

An atom is ______ (radioactive) if these forces
are unbalanced–if the nucleus has an excess of
internal energy

A

unstable

44
Q

An atom is unstable (radioactive) if these forces
are unbalanced–if the nucleus has an excess of
______

A

internal energy

45
Q

causes atoms to be radioactive

A

Instability of an atom’s nucleus
may result from an excess of
either neutrons or protons.

46
Q

How long do radionuclides stay radioactive?

A

*It depends on the kind of radioactive material.
*The rate of decay (half-life) is one of the characteristics of
radionuclides.

47
Q
  • is the time required for the disintegration of
    one-half of the radioactive atoms that are present when
    measurement starts.
  • It does not represent a fixed number of atoms that
    disintegrate, but a fraction
A

*Half-life (t1/2)

48
Q

3 types of half life

A
  • physical
  • biological
  • effective
49
Q

the time it takes for a radioactive atom to half
its original activity by 50%.

A

physical half-life

50
Q
  • is the time an organism takes
    to eliminate one half the amount of a compound or chemical on a strictly biological basis.
  • Thus, if a stable chemical compound were given to an individual and half of it were eliminated by the body (perhaps in urine) within three hours, the ________ half-life would be three hours.
A

biological half-life

51
Q
  • incorporates both the radioactive
    and biological half-lives.
  • It is used when health physicists calculate the dose
    received from an internal radiation source.
A

Effective Half-life

52
Q

To determine the effective half-life of a radionuclide in a
human, one needs to know the _______ half-life as
well as the ____ half-life of the radionuclide.

A

radioactive; biological

53
Q

_____tells how quickly the
radioactivity from the radionuclide will
decrease.
_____tells how active it
is now

A

half-life; number of curies

54
Q

As the nucleus emits radiation or disintegrates, the radioactive atom or radionuclide transforms to different ________. The process is called radioactive decay.

A

nuclides

55
Q

Can unstable atoms become stable?

A

continue radioactive decay until the forces in the nucleus are balanced
(STABLE)

56
Q

A radioactive atom will attempt to reach stability by
throwing off ____

A

nucleons

57
Q

This decay chain, or decay series, ends in a _________

A

stable nuclide

58
Q

*Until the last step, these radionuclides emit energy or
particle with each transformation and become another
radionuclide.

A

Decay Chains

59
Q

Radionuclide decay chains are important in
planning for the _______________ of
radioactive materials and waste and for ___________

A

management and disposal;site cleanup.

60
Q
A
60
Q

As radioactive decay progresses, the concentration of the original radionuclides decreases, while the concentration of their decay products increases and then ________ as
they undergo transformation.

A

decreases

61
Q

As radioactive decay progresses, the concentration of the
original radionuclides _______, while the concentration
of their decay products increases and then decreases as
they undergo transformation.

A

decreases

62
Q

The increasing concentration of
decay products and activity is called

A

ingrowth

63
Q

for a decay chain occurs when
each radionuclide decays at the same rate it is produced.

A

Radioactive equilibrium

64
Q

When the production and decay rates of each radionuclide
in the decay chain are equal, the chain has reached

A

radioactive equilibrium.

65
Q

However if the half-life of the decay product is much
longer than that of the original radionuclide,

A

equilibrium
cannot occur.

66
Q

Types of Radioactive

Equilibrium

The original radionuclide
and decay product half-lives
are similar

A

transient
equilibrium

66
Q
A
67
Q

Types of Radioactive

Equilibrium

The original radionuclide
has a much longer half-life

A

secular equilibrium

68
Q

Types of Radioactive

Equilibrium

The decay product has a longer
half-life

A

no equilibrium

69
Q

Modes of Radioactive Decay

 Stable nuclides of the lighter
elements have approximately equal
numbers of protons and neutrons.
 However, as Z(number of protons) increases, the `**stability
line’ curves upwards.
 Heavier nuclei need more and more
neutrons to be stable.

A

Stability

70
Q

Modes of Radioactive Decay

 A radio-nuclide above the
stability line decays by
β-emission.
 Because it loses a neutron
and gains a proton, it
moves diagonally towards
the stability line, as shown
on this graph.

A

Beta decay

70
Q

A plot of neutron number versus proton
number is also called .

A

Segre plot

71
Q

Modes

of Radioactive
Decay

A radio-nuclide above the
stability line decays by
β-emission.

A

Beta decay

72
Q

stable or unstable?

1:1 for _____ elements, and 3:2 for ____.

A

smaller; bigger

73
Q
  • is a sub-atomic particle with a small mass (similar to
    electrons) and no electrical charge.
  • not affected by the electrical or magnetic
    forces. It is shown by the letter ѵ(nu).
A

neutrino

74
Q

The neutrino was postulated first
by ________ in 1930 to
explain how beta decay could
conserve energy

A

Wolfgang Pauli

75
Q

____________ discovered a
much more massive nuclear
particle in 1932 and also named it a
neutron

A

James Chadwick

76
Q

coined the
term neutrino (the Italian
equivalent of “little neutral one”)

A

Enrico Fermi

77
Q

is an antimatter particle,
the counterpart to the neutrino.

A

antineuterino

78
Q

Occurs when the nucleus is too
large

A

Alpha Particle Emission/decay

79
Q

When the ratio of neutrons to
protons in the nucleus is too low,
certain atoms restore the balance
by emitting ___________.

A

alpha particles

80
Q

________ emitting atoms tend to be
very large atoms (high atomic
numbers).

A

alpha

81
Q

With some exceptions, naturally
occurring alpha emitters have
atomic numbers of at least __ (the
element lead).

A

82 (lead)

82
Q

What happens to atoms during alpha emission?

A

alpha particle is ejected
leaving The atom has then lost
two protons along with two
neutrons.

83
Q

Net effect is loss of 4 in mass
number and loss of 2 in
atomic number.

A

alpha emission

84
Q

occurs when the
neutron to proton ratio is too
great in the nucleus and
causes instability.
- Many radioactive nuclides
decay by β-emission

A

beta decay

85
Q

Beta decay

What happens is that one of
the _____ changes into a
proton (which stays in the
nucleus) and an electron
(which is emitted as a
β-particle).

A

neutrons

86
Q

particle with
same mass as an electron
but with a positive charge
(antimatter version of an
electron)

A

positron

87
Q

The atomic number goes UP by one and mass number remains
unchanged.

A

Beta Minus Decay

88
Q

The atomic number goes DOWN by one and mass number remains
unchanged.

A

Positron Decay

89
Q

A nuclear process in which a
nucleus with excess energy
following the emission of an
alpha particle or a beta
particle *emits energy without
changing its number
of protons or neutrons. *

A

Isomeric Transition

90
Q

occurs because the nucleus
is at too high an energy.

A

gamma decay

91
Q

Sometimes a nucleus that is still unstable
after a beta or alpha decay is still unstable
so may emit ________ to become
more stable.

A

gamma radiation

92
Q

is a process in
which a nucleus with excess energy
can get rid of that energy *without
altering its proton or neutron
count. *

A

Internal Conversion

93
Q
  • It can occur only if the amount of
    energy given to the orbital electron
    exceeds its binding energy.
  • X-rays are emitted as the atom
    attempts to restore its neutrality
A

Internal Conversion

94
Q

Thorium 232

A

Lead 208

95
Q

—- from the decay of uranium and thorium

A

Radon

96
Q

found in minerals and plants

A

Potassium-40

97
Q

found in plants and animal tissue

A

Carbon 14

98
Q

Uranium 238

A

Lead 206

99
Q

Uranium 235

A

Lead 207

100
Q

Neptunium 237

A

Bismuth 209

101
Q

Neptunium 237

A

Bismuth 209

RadProd (7 decks)

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