A table or chart of nuclides is a two-dimensional
graph
Graph may refer to:
Mathematics
*Graph (discrete mathematics), a structure made of vertices and edges
**Graph theory, the study of such graphs and their properties
*Graph (topology), a topological space resembling a graph in the sense of discret ...
of
isotope
Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...
s of the
chemical element
A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...
s, in which one axis represents the
number of neutrons (symbol ''N'') and the other represents the
number of protons (atomic number, symbol ''Z'') in the
atomic nucleus
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford at the Department_of_Physics_and_Astronomy,_University_of_Manchester , University of Manchester ...
. Each point plotted on the graph thus represents a
nuclide
Nuclides (or nucleides, from nucleus, also known as nuclear species) are a class of atoms characterized by their number of protons, ''Z'', their number of neutrons, ''N'', and their nuclear energy state.
The word ''nuclide'' was coined by the A ...
of a known or hypothetical element. This system of ordering nuclides can offer a greater insight into the characteristics of isotopes than the better-known
periodic table
The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows (" periods") and columns (" groups"). It is an icon of chemistry and is widely used in physics and other s ...
, which shows only elements and not their isotopes. The chart of the nuclides is also known as the Segrè chart, after Italian physicist
Emilio Segrè.
Description and utility
A chart or table of nuclides maps the nuclear, or
radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is conside ...
, behavior of nuclides, as it distinguishes the isotopes of an element. It contrasts with a periodic table, which only maps their chemical behavior, since isotopes (nuclides that are variants of the same element) do not differ chemically to any significant degree, with the exception of hydrogen. Nuclide charts organize nuclides along the X axis by their numbers of
neutron
The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...
s and along the Y axis by their numbers of
proton
A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...
s, out to the limits of the neutron and proton
drip lines. This representation was first published by Kurt Guggenheimer in 1934 and expanded by Giorgio Fea in 1935,
Emilio Segrè in 1945 or Glenn Seaborg. In 1958,
Walter Seelmann-Eggebert and Gerda Pfennig published the first edition of the
Karlsruhe Nuclide Chart. Its 7th edition was made available in 2006. Today, there are several nuclide charts, four of which have a wide distribution: the Karlsruhe Nuclide Chart, the Strasbourg Universal Nuclide Chart, the Chart of the Nuclides from the
Japan Atomic Energy Agency (JAEA), and the Nuclide Chart from
Knolls Atomic Power Laboratory in the United States. It has become a basic tool of the nuclear community.
Trends in the chart of nuclides
The trends in this section refer to the following chart, which shows ''Z'' increasing to the right and ''N'' increasing downward, a 90° clockwise rotation of the above landscape-orientation charts.
*
Isotope
Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...
s are nuclides with the same number of protons but differing numbers of neutrons; that is, they have the same atomic number and are therefore the same
chemical element
A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...
. Isotopes neighbor each other vertically. Examples include carbon-12, carbon-13, and carbon-14 in the table above.
*
Isotones are nuclides with the same number of neutrons but differing numbers of protons. Isotones neighbor each other horizontally. Examples include carbon-14, nitrogen-15, and oxygen-16 in the table above.
*
Isobars are nuclides with the same number of
nucleon
In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number.
Until the 1960s, nucleons were thought to be ele ...
s (i.e. mass number) but different numbers of protons and neutrons. Isobars neighbor each other diagonally from lower-left to upper-right. Examples include carbon-14, nitrogen-14, and oxygen-14 in the table above.
*
Isodiaphers are nuclides with the same difference between their numbers of neutrons and protons (''N'' − ''Z''). Like isobars, they follow diagonal lines, but at right angles to the isobar lines (from upper-left to lower-right). Examples include boron-10, carbon-12, and nitrogen-14 (as ''N'' − ''Z'' = 0 for each pair), or boron-12, carbon-14, and nitrogen-16 (as ''N'' − ''Z'' = 2 for each pair).
* Beyond the neutron
drip line along the lower left, nuclides decay by
neutron emission
Neutron emission is a mode of radioactive decay in which one or more neutrons are ejected from a Atomic nucleus, nucleus. It occurs in the most neutron-rich/proton-deficient nuclides, and also from excited states of other nuclides as in photodisin ...
.
* Beyond the proton drip line along the upper right, nuclides decay by
proton emission
Proton emission (also known as proton radioactivity) is a rare type of radioactive decay in which a proton is ejected from a atomic nucleus, nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay ...
. Drip lines have only been established for some elements.
* The
island of stability
In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclid ...
is a hypothetical region in the top right cluster of nuclides that contains isotopes far more stable than other
transuranic elements.
* There are no stable nuclides having an equal number of protons and neutrons in their nuclei with atomic number greater than 20 (i.e.
calcium
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...
) as can be readily observed from the chart. Nuclei of greater atomic number require an excess of neutrons for stability.
* The only stable nuclides having an odd number of protons and an odd number of neutrons are hydrogen-2 (
deuterium
Deuterium (hydrogen-2, symbol H or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen; the other is protium, or hydrogen-1, H. The deuterium nucleus (deuteron) contains one proton and one neutron, whereas the far more c ...
),
lithium-6
Naturally occurring lithium (3Li) is composed of two stable isotope ratio, stable isotopes, lithium-6 (6Li) and lithium-7 (7Li), with the latter being far more abundant on Earth. Both of the natural isotopes have an unexpectedly low nuclear bin ...
,
boron-10,
nitrogen-14
Natural nitrogen (7N) consists of two stable isotopes: the vast majority (99.6%) of naturally occurring nitrogen is nitrogen-14, with the remainder being nitrogen-15. Thirteen radioisotopes are also known, with atomic masses ranging from 9 to 23, ...
and (observationally)
tantalum-180m. This is because the
mass–energy of such atoms is usually higher than that of their neighbors on the same isobaric chain, so most of them are unstable to
beta decay
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which an atomic nucleus emits a beta particle (fast energetic electron or positron), transforming into an isobar of that nuclide. For example, beta decay of a neutron ...
.
* There are no stable nuclides with mass number 5 or 8. There are stable nuclides with all other mass numbers up to 208 with the exceptions of 147 and 151, which are represented by the very long-lived
samarium-147 and
europium-151. (
Bismuth-209
Bismuth-209 (Bi) is an isotope of bismuth, with the longest known half-life of any radioisotope that undergoes α-decay (alpha decay). It has 83 protons and a magic number of 126 neutrons, and an atomic mass of 208.9803987 amu (atomic mass unit ...
was found to be radioactive in 2003, but with a half-life of .)
* With the exception of the pair
tellurium-123 and
antimony-123, odd mass numbers are never represented by more than one stable nuclide. This is because the mass–energy is a
convex function
In mathematics, a real-valued function is called convex if the line segment between any two distinct points on the graph of a function, graph of the function lies above or on the graph between the two points. Equivalently, a function is conve ...
of atomic number, so all nuclides on an odd isobaric chain except one have a lower-energy neighbor to which they can decay by beta decay. See
Mattauch isobar rule. (
123Te is expected to decay to Sb, but the half-life appears to be so long that the decay has never been observed.)
* There are no stable nuclides having atomic number greater than ''Z'' = 82 (
lead
Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...
), although
bismuth
Bismuth is a chemical element; it has symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs nat ...
(''Z'' = 83) is stable for all practical human purposes and
thorium
Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and ha ...
(''Z'' = 90) and
uranium
Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...
(''Z'' = 92) are sufficiently long-lived to occur on Earth in large quantities. Elements with atomic numbers from 1 to 82 all have stable isotopes, with the exceptions of
technetium
Technetium is a chemical element; it has Symbol (chemistry), symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. Technetium and promethium are the only radioactive elements whose neighbours in the sense ...
(''Z'' = 43) and
promethium
Promethium is a chemical element; it has Symbol (chemistry), symbol Pm and atomic number 61. All of its isotopes are Radioactive decay, radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in the Earth's crust a ...
(''Z'' = 61).
Tables
For convenience, three different views of the data are available on Wikipedia: two sets of "segmented tables", and a single "unitized table (all elements)". The unitized table allows easy visualization of proton/neutron-count trends but requires simultaneous horizontal and vertical scrolling. The segmented tables permit easier examination of a particular chemical element with much less scrolling. Links are provided to quickly jump between the different sections.
Segmented tables
*
Table of nuclides (segmented, narrow)
*
Table of nuclides (segmented, wide)
Full table
The nuclide table below shows
nuclide
Nuclides (or nucleides, from nucleus, also known as nuclear species) are a class of atoms characterized by their number of protons, ''Z'', their number of neutrons, ''N'', and their nuclear energy state.
The word ''nuclide'' was coined by the A ...
s (often loosely called "isotopes", but this term properly refers to nuclides with the same atomic number, see above), including all with
half-life Half-life is a mathematical and scientific description of exponential or gradual decay.
Half-life, half life or halflife may also refer to:
Film
* Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang
* ''Half Life: ...
of at least one day.
[The data for these tables came from ]Brookhaven National Laboratory
Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratories, United States Department of Energy national laboratory located in Upton, New York, a hamlet of the Brookhaven, New York, Town of Brookhaven. It w ...
, which has an interactiv
Table of Nuclides
with data on ~3000 nuclides. They are arranged with increasing
atomic numbers from left to right and increasing
neutron
The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...
numbers from top to bottom.
Cell color denotes the half-life of each nuclide; if a border is present, its color indicates the half-life of the most stable
nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state levels (higher energy levels). "Metastable" describes nuclei whose excited states have Half-life, half-lives of ...
. In graphical browsers, each nuclide also has a
tool tip indicating its half-life.
Each color represents a certain range of length of half-life, and the color of the border indicates the half-life of its nuclear isomer state. Some nuclides have multiple nuclear isomers, and this table notes the one with the longest half-life.
Dotted borders mean that a nuclide has a nuclear isomer with a half-life in the same range as the ground state nuclide.
The dashed lines between several nuclides of the first few elements are the experimentally determined proton and neutron
drip lines.
References
External links
Chart of the Nuclides 2014 (Japan Atomic Energy Agency)Interactive Chart of Nuclides (Brookhaven National Laboratory)Nucleonica web driven nuclear science* app for mobiles:
Android or
Apple– for PC us
The Live Chart of Nuclides - IAEA The Colourful Nuclide Chart by Edward Simpson of Australian National University
Another example of a Chart of Nuclides from KoreaData up to Jan 1999 only
{{DEFAULTSORT:Table Of Nuclides
Tables of nuclides