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 discre ...
of
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( mass number ...
s of the elements, in which one axis represents the
number of neutrons (symbol ''N'') and the other represents the
number of protons
The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of every ...
(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 based on the 1909 Geiger–Marsden experiments, Geiger–Marsden gold foil experiment. After th ...
. Each point plotted on the graph thus represents a
nuclide
A nuclide (or nucleide, from nucleus, also known as nuclear species) is 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 Truma ...
of a known or hypothetical
chemical element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...
. 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 (chemical) elements, is a rows and columns arrangement of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of ...
, which shows only elements and not their isotopes. The chart of the nuclides is also known as the Segrè chart, after the Italian physicist
Emilio Segrè
Emilio Gino Segrè (1 February 1905 – 22 April 1989) was an Italian-American physicist and Nobel laureate, who discovered the elements technetium and astatine, and the antiproton, a subatomic antiparticle, for which he was awarded the N ...
.
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 consi ...
, 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 which 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 , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behav ...
s and along the Y axis by their numbers of
protons, 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
Emilio Gino Segrè (1 February 1905 – 22 April 1989) was an Italian-American physicist and Nobel laureate, who discovered the elements technetium and astatine, and the antiproton, a subatomic antiparticle, for which he was awarded the N ...
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
*
Isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( mass number ...
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 species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...
. 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
nucleons
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 (nucleon number).
Until the 1960s, nucleons w ...
(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
Drip line may refer to:
* Nuclear drip line, the lines beyond which protons or neutrons leak out of nuclei
* Tree drip line, the area defined by the outermost circumference of a tree canopy where water drips from and onto the ground, useful for ...
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 nucleus. It occurs in the most neutron-rich/proton-deficient nuclides, and also from excited states of other nuclides as in photoneutron emission and ...
.
* 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 nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case ...
. Drip lines have only been established for some elements.
* The
island of stability is a hypothetical region in the top right cluster of nuclides that contains isotopes far more stable than other
transuranic elements
The transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, which is the atomic number of uranium. All of these elements are unstable and decay radioactively into other 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 with the 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 t ...
) 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,
lithium-6,
boron-10
Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the ''boron group'' it has th ...
,
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. Fourteen radioisotopes are also known, with atomic masses ranging from 10 to 2 ...
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 a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For e ...
.
* There are no stable nuclides with mass numbers 5 or 8. There are stable nuclides with all other mass numbers up to 208 with the exceptions of 147 and 151. (
Bismuth-209
Bismuth-209 (209Bi) is the 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 u ...
was found to be radioactive in 2003, but with a half-life of 1.9×10
19 years.)
* With the exception of the pair
tellurium-123 and
antimony-123
Antimony (51Sb) occurs in two stable isotope, stable isotopes, 121Sb and 123Sb. There are 35 artificial radioisotope, radioactive isotopes, the longest-lived of which are 125Sb, with a half-life of 2.75856 years; 124Sb, with a half-life of 60.2 da ...
, 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 points on the graph of the function lies above the graph between the two points. Equivalently, a function is convex if its epigraph (the set of poin ...
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
123Sb, 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 with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate ...
), although
bismuth
Bismuth is a chemical element with the 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 ...
(''Z'' = 83) is stable for all practical human purposes. Elements with atomic numbers from 1 to 82 all have stable isotopes, with the exceptions of
technetium (''Z'' = 43) and
promethium
Promethium is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in Earth's crust at any given time. Promethium is one of onl ...
(''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 visualizion 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)
These isotope tables show all of the known isotopes of the chemical elements, arranged with increasing atomic number from left to right and increasing neutron number from top to bottom.
Half lives are indicated by the color of each isotope's ...
*
Table of nuclides (segmented, wide)
These isotope tables show all of the known isotopes of the chemical elements, arranged with increasing atomic number from left to right and increasing neutron number from top to bottom.
half-life, Half lives are indicated by the color of eac ...
Full table
The nuclide table below shows
nuclide
A nuclide (or nucleide, from nucleus, also known as nuclear species) is 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 Truma ...
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 (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...
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 laboratory located in Upton, Long Island, and was formally established in 1947 at the site of Camp Upton, a former U.S. Army base and Japanese internment c ...
which has an interactiv
Table of Nuclides
with data on ~3000 nuclides. They are arranged with increasing
atomic numbers
The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of ever ...
from left to right and increasing
neutron
The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behav ...
numbers from top to bottom.
Cell color denotes the
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...
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 higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ...
. In graphical browsers, each nuclide also has a
tool tip
The tooltip, also known as infotip or hint, is a common graphical user interface (GUI) element in which, when hovering over a screen element or component, a text box displays information about that element, such as a description of a button's f ...
indicating its half-life.
Each color represents a certain range of length of
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...
, and the color of the border indicates the
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...
of its
nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ...
state. Some nuclides have multiple
nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ...
s, and this table notes the longest one.
Dotted borders mean that a nuclide has a
nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ...
, and their color is represented the same way as for their normal counterparts.
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 use '
The Live Chart of Nuclides - IAEA ''
* '
The Colourful Nuclide Chart'', by Dr 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