Nuclear chemistry

Nuclide

• nuclide (or nucleide, nuclear species) (נוּקליד)
  • nuclides’ classification:
    • isotopes (equal $Z$) (see Wikipedia: Isotope vs. nuclide)
    • isotones (equal $A$)
    • isobars (equal $N$)
• atomic nucleus (גרעין האטום)
  • “the small, dense region consisting of protons and neutrons at the center of the atom” (Wikipedia)

	symbol			aka
atomic number	$Z$	the number of protons in the nucleus of an atom	also the number of electrons in a neutral atom	nuclear charge number
neutron number	$N$	the number of neutrons in the nucleus of an atom
mass number	$A=Z+N$	the number of nucleons (protons and neutrons)	It is approximately equal to the atomic mass of the atom in unified atomic mass units	atomic mass number or nucleon number
neutron excess	$D=N-Z$

Nuclear stability

• nuclear binding energy (אנרגיית הקשר הגרעינית)
  • mass defect
• valley of stability
• island of stability
• metastability
• stable nuclides
• magic numbers
• radioactive
• radioisotope – an atom containing a radionuclide
• radionuclide – a radioactive nuclide

Nuclear reaction

• nuclear reaction
  • ”may refer either to a change in a nuclide induced by collision with another particle or to a spontaneous change of a nuclide without collision” (Wikipedia)
  • “A change that a nucleus undergoes (such as a nuclear transmutation)” (Jones, 2016)
• nuclear equation
  • ”A summary of the changes in a nuclear reaction, written in a form resembling a chemical equation.” (Jones, 2016)
• nuclear chain reaction (תגובת שרשרת גרעינית)
• nuclear fusion (היתוך גרעיני)
  • ${}_{}^{}{}_1^2\mathrm{H}+{}_{}^{}{}_1^3\mathrm{H}\to {}_{}^{}{}_2^4\mathrm{H}+{}_{}^{}{}_0^1\mathrm{n}+\mathrm{energy}$
• nuclear fission (ביקוע גרעיני)
  • ${}_{}^{}{}_0^1\mathrm{n}+{}_{}^{}{}_{92}^{235}\mathrm{U}\to {}_{}^{}{}_{92}^{236}\mathrm{U}\to {}_{}^{}{}_{36}^{92}\mathrm{Kr}+{}_{}^{}{}_{56}^{141}\mathrm{Ba}+3{}_{}^{}{}_0^1\mathrm{n}+\mathrm{energy}$
  • induced fission
• nuclear transformation

Radioactive decay

• radioactivity

• radioactive decay (or nuclear decay, or radioactivity) (דעיכה רדיואקטיבית)

• induced radioactivity (or artificial radioactivity)

  • in contrast to “natural radioactivity”

• spontaneous fission

• parent nucleus

  • ”In a nuclear reaction, the nucleus that undergoes disintegration or transmutation” (Jones, 2016)

• daughter nucleus (or daughter product, decay product) (תוצר דעיכה)

  • “A nucleus that is the product of a nuclear decay.” (Jones, 2016)

• intermediate nucleus

• decay chain (or radioactive series) (שרשרת דעיכה)

• alpha radiation (or alpha rays)

  • alpha decay (or α-decay) ${}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}}\mathrm{X}\to {}_{}^{}{}_{\mathrm{Z}-2}^{\mathrm{A}-4}\mathrm{Y}+{}_{}^{}{}_2^4\mathrm{He}$

• beta radiation (or beta ray)

  • beta decay (or β-decay)
    • ${}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}}\mathrm{X}\to {}_{}^{}{}_{\mathrm{Z}+1}^{\mathrm{A}}\mathrm{Y}+\mathrm{e}{}^{-}+\bar{\nu }{}_e$
    • ${}_{}^{}{}_0^1\mathrm{n}\to {}_{}^{}{}_1^1\mathrm{p}+{}_{}^{}{}_{-1}^0\mathrm{e}$
  • positron emission (or beta plus decay, β+ decay)
    • ${}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}}\mathrm{X}\to {}_{}^{}{}_{\mathrm{Z}-1}^{\mathrm{A}}\mathrm{Y}+\mathrm{e}{}^{+}+\nu {}_e$
    • ${}_{}^{}{}_1^1\mathrm{p}\to {}_{}^{}{}_0^1\mathrm{n}+{}_{}^{}{}_1^0\mathrm{e}$

• proton radiation

• neutron radiation ${}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}}\mathrm{X}\to {}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}-1}\mathrm{Y}+{}_{}^{}{}_0^1\mathrm{n}$

• electron capture

  • ${}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}}\mathrm{X}+{}_{}^{}{}_{-1}^0\mathrm{e}\to {}_{}^{}{}_{\mathrm{Z}-1}^{\mathrm{A}}\mathrm{Y}$
  • ${}_{}^{}{}_1^1\mathrm{p}+{}_{}^{}{}_{-1}^0\mathrm{e}\to {}_{}^{}{}_0^1\mathrm{n}$

• gamma radiation (or gamma ray)

  • gamma decay
  • ${}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}m}\mathrm{X}\to {}_{}^{}{}_{\mathrm{Z}}^{\mathrm{A}}\mathrm{X}+\gamma$

	particle	${}_Z^A{\mathrm{E}}^q$	${}_{}^{}{}_q^A\mathrm{x}$	mass ($\mathrm{u}$)
alpha particle	Helium-4	$\alpha$, $\alpha {}^{2+}$, $\mathrm{He}{}^{2+}$, ${}_2^4\mathrm{He}{}^{2+}$		$\approx 4.0015$
β− particle	electron	$\beta$	${}_{}^{}{}_{-1}^0\mathrm{e}$, ${}_{}^{}{}_{-1}^0\beta$	$1m_{\mathrm{e}}$
β+ particle	antielectron	$\beta {}^{+}$, $\mathrm{e}{}^{+}$	${}_{}^{}{}_{+1}^0\mathrm{e}$, ${}_{}^{}{}_{+1}^0\beta$	$1m_{\mathrm{e}}$
gamma	photon	$\gamma$	${}_{}^{}{}_0^0\gamma$	0

Half-life

• half-life ($t_{1/2}$), where:
  • $N(t)=N_0{e}^{-\lambda t}$ is an exponential decay function, where $\lambda$ is the decay constant. It gives the amount remaining after time $t$.
  • $t_{1/2}=\frac{\ln (2)}{\lambda }$ is the time required for a quantity to reduce to half of its initial value.
  • $N(n{t}_{1/2})=N_0\cdot (1/2{)}^n$ is the amount after $n$ half-lives.
    • $\frac{1}{2}$ is the decay factor per half-life.
    • $n=t/t_{1/2}$
• $\frac{dN}{dt}=-\lambda N$
• $A=-\frac{dN}{dt}=\lambda N$ is the activity

Measurement

quantity		SI unit	other units
activity (or total activity) ($A$)	rate of decay in a sample	$\mathrm{B}$	$\mathrm{Cu}$
specific activity ($a$)	activity per unit mass	$B/kg$
radiation exposure ($X$)	ionization produced	$C/kg$	$\mathrm{R}$
absorbed dose ($D$)	absorbed dose of ionizing radiation	$\mathrm{Gy}$	$\mathrm{rad}$
equivalent dose ($H$)	absorbed dose adjusted for radiation type damage	$\mathrm{Sv}$	$\mathrm{rem}$
effective dose ($E$)		$\mathrm{Sv}$	$\mathrm{rem}$

units

• becquerel ($\mathrm{B}$) (בקרל) ($1\mathrm{B}=1{\mathrm{s}}^{-1}$) an activity of one per second on average
• curie ($\mathrm{Cu}$), $1\mathrm{Cu}=3.7\times 10^{10}\mathrm{B}$
• gray ($\mathrm{Gy}$), $1\mathrm{Gy}=1\mathrm{J}\cdot \mathrm{k}{\mathrm{g}}^{-1}$
• rad ($\mathrm{rad}$), $1\mathrm{rad}=0.01\mathrm{Gy}$
• röntgen (or roentgen) ($\mathrm{R}$), $1\mathrm{R}=2.58\times 10^{-4}C/kg$
• roentgen equivalent man (rem), $1\mathrm{rem}=10^{-2}\mathrm{Sv}$
• sievert ($\mathrm{Sv}$), $1\mathrm{Sv}=1{\mathrm{m}}^2\cdot {\mathrm{s}}^{-2}$
• lethal dose
  • median lethal dose (${\text{LD}}_{50}$)
    • “the dose required to kill half the members of a tested population after a specified test duration” (Wikipedia)
    • $\approx 500\mathrm{rem}$

Applications

• nuclear power (אנרגיה גרעינית)
• nuclear reactor (כור גרעיני)
  • breeder reactor (כור תרבית, כור דוגר)
• nuclear medicine (or nuclear radiology) (רפואה גרעינית)
• medical imaging
• radiometric dating (or radioactive dating) (תיארוך רדיומטרי)
• radioactive waste

Realted topics

• radiochemistry
• radiation chemistry
• nuclear physics

References

• Jones, Loretta (2016). Chemical Principles. W. H. Freeman.