Nuclear Chemistry and Radiation Review

Comprehensive vocabulary flashcard set covering nuclear chemistry fundamentals, nuclear decay equations, radiation types, biological radiation effects, radiocarbon dating, medical imaging/therapy, food irradiation, nuclear fission, reactors, waste management, and nuclear fusion.

Atomic Number ($Z$)

The number of protons contained in the nucleus of an atom, which uniquely defines the element.

Mass Number ($A$)

The total sum of protons and neutrons present in the nucleus of an atom.

Neutrons Calculation Formula

$$\text{Number of neutrons} = \text{Mass number } (A) - \text{Atomic number } (Z)$$

Isotopes

Atoms of the same element that have the same number of protons but a different number of neutrons.

Stable Isotopes

Isotopes that do not undergo spontaneous decay; there are $264$ known stable isotopes among all elements.

Naturally Occurring Unstable Isotopes

Isotopes found in nature that spontaneously emit radiation; there are $300$ known naturally occurring unstable isotopes.

Radioisotope

An unstable radioactive isotope that spontaneously emits energy/radiation to form a more stable nucleus.

Radioactivity

The nuclear radiation spontaneously emitted by an unstable radioactive isotope.

Artificial Isotopes

Radioactive isotopes synthesized artificially in laboratory settings by nuclear bombardment.

Carbon-12 Nuclear Symbol

$^{12}_6\text{C}$, representing an atom with $6$ protons and $6$ neutrons.

Carbon-13 Nuclear Symbol

$^{13}_6\text{C}$, representing an atom with $6$ protons and $7$ neutrons.

Carbon-14 Nuclear Symbol

$^{14}_6\text{C}$, representing an atom with $6$ protons and $8$ neutrons.

Sulfur-30 Symbol Notation

$^{30}_{16}\text{S}$, indicating $16$ protons and $14$ neutrons.

Iodine-131 Symbol Notation

$^{131}_{53}\text{I}$, indicating $53$ protons and $78$ neutrons.

Alpha Particle ($\alpha$)

A high-energy, heavy particle containing $2$ protons and $2$ neutrons, identical to a helium nucleus.

Alpha Particle Symbols

$\alpha$ or $^4_2\text{He}$, possessing a charge of $+2$ and a mass number of $4$.

Beta Particle ($\beta$)

A high-energy electron emitted from a radioactive nucleus when a neutron converts into a proton.

Beta Particle Symbols

$\beta$ or $^0_{-1}\text{e}$, possessing a charge of $-1$ and a negligible mass number of $0$.

Beta Particle Formation Reaction

$^1_0\text{n} \rightarrow ^1_1\text{p} + ^0_{-1}\text{e}$, converting a neutron into a proton and an electron.

Positron ($\beta^+$)

The antiparticle of a beta particle, possessing a charge of $+1$ and a mass equal to an electron.

Positron Symbols

$\beta^+$ or $^0_{+1}\text{e}$, possessing a charge of $+1$ and an effective mass number of $0$.

Positron Formation Reaction

$^1_1\text{p} \rightarrow ^1_0\text{n} + ^0_{+1}\text{e}$, converting a proton into a neutron and a positron.

Gamma Ray ($\gamma$)

High-energy electromagnetic radiation released from a radioactive nucleus with no mass and no charge.

Proton Symbol

$^1_1\text{p}$ or $^1_1\text{H}$, having a charge of $+1$ and a mass number of $1$.

Neutron Symbol

$^1_0\text{n}$, having zero charge and a mass number of $1$.

Alpha Radiation Shielding

Requires paper, clothing, or human skin to block; alpha particles have the greatest mass among emitted particles.

Beta Radiation Shielding

Requires heavy clothing, lab coats, or gloves to block; beta particles have light mass.

Gamma Radiation Shielding

Requires dense lead shielding or a thick concrete wall to block due to its extreme high energy.

Radiation Protection Factors

Reducing exposure time, increasing distance from the radiation source, and using proper shielding.

Radioactive Decay

The process by which an unstable radioactive nucleus emits radiation, changing into a new nucleus.

Nuclear Equation Balancing Rules

The sum of mass numbers ($A$) and atomic numbers ($Z$) must be equal on both sides of the equation.

Alpha Emission

Nuclear decay in which an alpha particle ($^4_2\text{He}$) is emitted, reducing mass number by $4$ and atomic number by $$2$.

Uranium-238 Alpha Decay Equation

$$^{238}_{92}\text{U} \rightarrow ^{234}_{90}\text{Th} + ^4_2\text{He}$$

Americium-241 Alpha Decay Equation

$$^{241}_{95}\text{Am} \rightarrow ^{237}_{93}\text{Np} + ^4_2\text{He}$$

Radium-226 Alpha Decay Product

Radon-222 ($^{222}_{86}\text{Rn}$), formed via $^{226}_{88}\text{Ra} \rightarrow ^{222}_{86}\text{Rn} + ^4_2\text{He}$.

Einsteinium-252 Alpha Decay Product

Berkelium-248 ($^{248}_{97}\text{Bk}$), produced by losing $4$ mass units and $2$ protons.

Beta Emission

Nuclear decay emitting a beta particle ($^0_{-1}\text{e}$); $1$ neutron is converted to $1$ proton, increasing atomic number by $1$.

Potassium-42 Beta Decay Equation

$$^{42}_{19}\text{K} \rightarrow ^{42}_{20}\text{Ca} + ^0_{-1}\text{e}$$

Cobalt-60 Beta Decay Equation

$$^{60}_{27}\text{Co} \rightarrow ^{60}_{28}\text{Ni} + ^0_{-1}\text{e} + \gamma$$

Thorium-234 Beta Decay Product

Protactinium-234 ($^{234}_{91}\text{Pa}$), formed by $^{234}_{90}\text{Th} \rightarrow ^{234}_{91}\text{Pa} + ^0_{-1}\text{e}$.

Tin-126 Beta Decay Result

Antimony-126 ($^{126}_{51}\text{Sb}$), according to $^{126}_{50}\text{Sn} \rightarrow ^{126}_{51}\text{Sb} + ^0_{-1}\text{e}$.

Zinc-69 Beta Decay Result

Gallium-69 ($^{69}_{31}\text{Ga}$), according to $^{69}_{30}\text{Zn} \rightarrow ^{69}_{31}\text{Ga} + ^0_{-1}\text{e}$.

Iron-59 Beta Decay Equation

$$^{59}_{26}\text{Fe} \rightarrow ^{59}_{27}\text{Co} + ^0_{-1}\text{e}$$

Positron Emission

Nuclear decay emitting a positron ($^0_{+1}\text{e}$); $1$ proton is lost and $1$ neutron is gained, decreasing atomic number by $$1$.

Manganese-49 Positron Decay Equation

$$^{49}_{25}\text{Mn} \rightarrow ^{49}_{24}\text{Cr} + ^0_{+1}\text{e}$$

Boron-8 Positron Decay Product

Beryllium-8 ($^{8}_{4}\text{Be}$), formed by $^{8}_{5}\text{B} \rightarrow ^{8}_{4}\text{Be} + ^0_{+1}\text{e}$.

Mercury-178 Positron Decay Equation

$$^{178}_{80}\text{Hg} \rightarrow ^{178}_{79}\text{Au} + ^0_{+1}\text{e}$$

Platinum-190 Alpha Decay Equation

$$^{190}_{78}\text{Pt} \rightarrow ^{186}_{76}\text{Os} + ^4_2\text{He}$$

Gamma Emission

Nuclear decay releasing high-energy gamma rays ($\gamma$), causing no change in atomic or mass numbers.

Metastable Isotope

An unstable isotope (like $^{99\text{m}}_{43}\text{Tc}$) in a higher-energy state that decays by gamma emission to a more stable state.

Technetium-99m Gamma Emission Equation

$$^{99\text{m}}_{43}\text{Tc} \rightarrow ^{99}_{43}\text{Tc} + \gamma$$

Half-Life ($t_{1/2}$)

The time required for one-half of a sample of a radioactive isotope to undergo nuclear decay.

Half-Life Independence

The half-life of a radioisotope is a physical property independent of sample size, temperature, and pressure.

Cobalt-60 Half-Life

$5.27\,\text{years}$; emits beta particles and gamma rays used in cancer radiation therapy.

Carbon-14 Half-Life

$5730\,\text{years}$; naturally occurring beta emitter used in archaeological radiocarbon dating.

Potassium-40 Half-Life

$1.3 \times 10^9\,\text{years}$; naturally occurring radioisotope emitting beta and gamma radiation.

Radium-226 Half-Life

$1600\,\text{years}$; naturally occurring alpha emitter.

Strontium-90 Half-Life

$38.1\,\text{years}$; naturally occurring alpha emitter.

Uranium-238 Half-Life

$4.51 \times 10^9\,\text{years}$ (or $4.5 \times 10^9\,\text{y}$); naturally occurring alpha emitter.

Chromium-51 Half-Life

$28\,\text{days}$; medical gamma emitter.

Iodine-131 Half-Life

$8.05\,\text{days}$ (or $8\,\text{d}$); medical beta and gamma emitter used for thyroid studies.

Iron-59 Half-Life

$44\,\text{days}$; medical beta and gamma emitter.

Radon-222 Half-Life

$3.8\,\text{days}$ (or $3.82\,\text{days}$); naturally occurring gaseous alpha emitter.

Technetium-99m Half-Life

$6.0\,\text{hours}$; widely used diagnostic medical gamma emitter.

Phosphorus-32 Half-Life

$14\,\text{days}$; decays by beta emission into Sulfur-32.

Iodine-131 Decay Mass Calculation (32 days)

A $100.\,\text{mg}$ sample of Iodine-131 ($t_{1/2} = 8.0\,\text{days}$) decreases to $6.25\,\text{mg}$ after $4$ half-lives ($32\,\text{days}$).

Strontium-90 Decay Calculation (152.4 years)

A $36\,\text{mg}$ sample of Strontium-90 ($t_{1/2} = 38.1\,\text{years}$) decreases to $2.3\,\text{mg}$ after $4$ half-lives ($152.4\,\text{years}$).

Iodine-123 Decay Calculation (26 hours)

A $64\,\text{mg}$ sample of Iodine-123 ($t_{1/2} = 13\,\text{h}$) decreases to $16\,\text{mg}$ after $2$ half-lives ($26\,\text{hours}$).

Technetium-99m Decay Calculation (24 hours)

A $120.0\,\text{mg}$ sample of Technetium-99m ($t_{1/2} = 6.0\,\text{h}$) decreases to $7.5\,\text{mg}$ after $4$ half-lives ($24.0\,\text{hours}$).

Decay Half-Life Determination (0.36 g to 90 mg)

Decreasing from $0.36\,\text{g}$ ($360\,\text{mg}$) to $90\,\text{mg}$ requires $2$ half-lives; if elapsed time is $22\,\text{min}$, the half-life is $11\,\text{min}$.

Radiocarbon Dating

A technique using the decay of Carbon-14 ($t_{1/2} = 5730\,\text{years}$) relative to Carbon-12 to determine the age of organic artifacts.

Carbon-14 Living Organism Equilibrium

In living organisms, the ratio of radioactive Carbon-14 to stable Carbon-12 remains constant through atmospheric exchange.

Carbon-14 Decay Post-Mortem

When an organism dies, Carbon-14 intake stops, and existing Carbon-14 continuously decays without being replenished.

Dead Sea Scrolls Age Calculation

Determined to be $2000\,\text{years}$ old; calculating $\frac{2000\,\text{years}}{5730\,\text{years}} = 0.35$ half-lives passed.

Transuranium Elements

Artificial, synthetic elements with atomic numbers greater than $92$ ($Z > 92$).

Synthesis of Elements up to Z = 101

Produced by bombarding target nuclei with light particles such as alpha particles ($\alpha$) or neutrons ($\text{n}$).

Synthesis of Elements beyond Z = 101

Requires bombardment of target nuclei with heavier nuclear projectile ions.

Maximum Synthesized Element Atomic Number

Elements up to atomic number $118$ have been synthesized in laboratory settings.

Neptunium Synthesis Reaction

$^{238}_{92}\text{U} + ^2_1\text{H} \rightarrow ^{239}_{92}\text{U} + ^1_1\text{H}$, followed by beta decay of Uranium-239 to Neptunium-239.

Uranium-239 Half-Life and Decay

$t_{1/2} = 23.5\,\text{minutes}$; decays by beta emission to form Neptunium-239 ($^{239}_{93}\text{Np}$).

Neptunium-239 Half-Life and Decay

$t_{1/2} = 2.33\,\text{days}$; decays by beta emission to form Plutonium-239 ($^{239}_{94}\text{Pu}$).

Plutonium-239 Half-Life

$t_{1/2} > 24,100\,\text{years}$; a radioactive transuranium element produced from Neptunium decay.

Transmutation

The nuclear process where a stable nucleus is converted into a radioactive or different nucleus by bombardment with particles.

Boron-10 Alpha Bombardment Reaction

$^4_2\text{He} + ^{10}_5\text{B} \rightarrow ^{13}_7\text{N} + ^1_0\text{n}$, yielding radioactive Nitrogen-13 and a neutron.

Technetium-98 Neutron Bombardment

Bombarding $^{98}_{43}\text{Tc}$ with a neutron while releasing an alpha particle produces Rhodium-95 ($^{95}_{41}\text{Nb}$ or product nucleus).

Background Radiation

Radiation received during normal daily life from natural and man-made background sources.

Natural Background Radiation Share

Constitutes $82\%$ of total average background radiation exposure in the United States.

Man-made Background Radiation Share

Constitutes $18\%$ of average exposure, with medical X-rays ($11\%$) and nuclear medicine ($4\%$) as main contributors.

Potassium-40 Exposure in Humans

$0.01\%$ of potassium is Potassium-40; a $60\,\text{kg}$ person has ~$20\,\text{mg}$ of Potassium-40 decaying inside their body.

Radon Gas Formation

Radon ($\text{Rn}$) is a radioactive noble gas continuously formed in the earth via the decay of naturally occurring Uranium.

Radon Background Contribution

Radon accounts for $55\%$ of all background radiation exposure in the United States.

Radon Decay Chain Hazard

Inhaled Radon-222 decays into non-gaseous alpha-emitting daughter nuclei (Polonium-218, Lead-214) that linger in lungs and damage tissue.

EPA Indoor Radon Limit

$4\,\text{pCi/L}$ (picoCuries per liter) of air.

Affected Homes by Radon Contamination

Approximately $8\text{ million}$ homes in the United States are affected by radon contamination.

Curie (Ci)

A unit measuring radioactivity equal to $3.7 \times 10^{10}\text{ disintegrations/second}$.

Sub-Curie Unit Conversions

$1\,\text{Ci} = 1,000\,\text{mCi}$ (millicuries) and $1\,\text{Ci} = 1,000,000\,\mu\text{Ci}$ (microcuries).

Becquerel (Bq)

The SI unit of radioactivity defined as $1\text{ disintegration/second}$ ($1\,\text{Ci} = 3.7 \times 10^{10}\,\text{Bq}$).

Rad (Radiation Absorbed Dose)

A unit measuring the amount of radiation energy absorbed by one gram of a substance.

Rem (Radiation Equivalent for Man)

A measure of radiation dose that factors in both absorbed energy and potential tissue damage ($1\,\text{rem}$ produces equal tissue damage regardless of radiation type).

Average Annual Radiation Dose

The average annual radiation dose absorbed per person is approximately $0.27\,\text{rem}$.