Isotopes are variants of a particular chemical element which differ in neutron numberand consequently in mass number. All isotopes of a given element have the same number of protons in each atom. The What are the stable isotopes of nitrogen yahoo dating of protons within the atom's nucleus is called atomic number and is equal to the number of electrons in the neutral non-ionized atom. Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons.
The number of nucleons both protons and neutrons in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number.
For example, carboncarbon and carbon are three isotopes of the element carbon with mass numbers 12, 13 and 14 respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons, so that the neutron numbers of these isotopes are 6, 7 and 8 respectively. A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example carbon with 6 protons and 7 neutrons. The nuclide concept referring to individual nuclear species emphasizes nuclear properties over chemical properties, whereas the isotope concept grouping all atoms of each element emphasizes chemical over nuclear.
The neutron number has large effects on nuclear properties, but its effect on chemical properties is negligible for most elements. Even in the case of the lightest elements where the ratio of neutron number to atomic number varies the most between isotopes it usually has only a small effect, although it does matter in some circumstances for hydrogen, the lightest element, the isotope effect is large enough to strongly affect biology.
What are the stable isotopes of nitrogen yahoo dating isotopes originally also isotopic elements now sometimes isotopic nuclides  is intended to imply comparison like synonyms or isomersfor example: However, because isotope is the older term, it is better known than nuclideand is still sometimes used in contexts where nuclide might be more appropriate, such as nuclear technology and nuclear medicine.
Isotopes are atoms of the same element having the same numbers of protons atomic numberbut different numbers of neutrons. They have same chemical properties, or very nearly so, due to the same electron configuration, but different physical properties.
The letter m is sometimes appended after the mass number to indicate a nuclear isomera metastable or energetically-excited nuclear state as opposed to the lowest-energy ground statefor example m 73 Ta tantalumm. The common pronunciation of the AZE notation is different from how it is written: For example, 14 C is a radioactive form of carbon, whereas 12 C and 13 C are stable isotopes. There are about naturally occurring nuclides on Earth,  of which are primordial nuclidesmeaning that they have existed since the Solar System 's formation.
Primordial nuclides include 32 nuclides with very long half-lives over million years and that are formally considered as " stable nuclides ",  because they have not been observed to decay. In most cases, for obvious reasons, if an element has stable isotopes, those isotopes predominate in the elemental abundance found on Earth and in the Solar System. However, in the cases of three elements tellurium, indium, and rhenium the most abundant isotope found in nature is actually one or two extremely long-lived radioisotope s of the element, despite these elements having one or more stable isotopes.
Of "What are the stable isotopes of nitrogen yahoo dating" nuclides never observed to decay, only 90 of these all from the first 40 elements are theoretically stable to all known forms of decay. Element 41 niobium is theoretically unstable via spontaneous fissionbut this has never been detected. Many other stable nuclides are in theory energetically susceptible to other known forms of decay, such as alpha decay or double beta decay, but no decay products have yet been observed, and so these isotopes are said to be "observationally stable".
The predicted half-lives for these nuclides often greatly exceed the estimated age of the universe, and in fact
What are the stable isotopes of nitrogen yahoo dating are also 27 known radionuclides see primordial nuclide with half-lives longer than the age of the universe.
Adding in the radioactive nuclides that have been created artificially, there are 3, currently known nuclides. See list of nuclides for details.
The existence of isotopes was first suggested in by the radiochemist Frederick Soddybased on studies of radioactive decay chains that indicated about 40 different species referred to as radioelements i. Several attempts to separate What are the stable isotopes of nitrogen yahoo dating new radioelements chemically had failed.
Soddy proposed that several types of atoms differing in radioactive properties could occupy the same place in the table. Richards found variations between the atomic weight of lead from different mineral sources, attributable to variations in isotopic composition due to different radioactive origins. The first evidence for multiple isotopes of a stable non-radioactive element was found by J. Thomson in as part of his exploration into the composition of canal rays positive ions.
Each stream created a glowing patch on the plate at the point it struck. Thomson observed two separate patches of light on the photographic plate see imagewhich suggested two different parabolas of deflection. Thomson eventually concluded that some of the atoms in the neon gas were of higher mass than the rest. Aston subsequently discovered multiple stable isotopes for numerous elements using a mass spectrograph. In Aston studied neon with sufficient resolution to show that the two isotopic masses are very close to the integers 20 and 22, and that neither is equal to the known molar mass This is an example of Aston's whole number rule for isotopic masses, which states that large deviations of elemental molar masses from integers are primarily due to the fact that the element is a mixture of isotopes.
Aston similarly showed [ when? A neutral atom has the same number of electrons as protons. Thus different isotopes of a given element all have the same number of electrons and share a similar electronic structure. Because the chemical behavior of an atom is largely determined by its electronic structure, different isotopes exhibit nearly identical chemical behavior.
The main exception to this is the kinetic isotope effect: This is most pronounced by far for protium 1 Hdeuterium 2 Hand tritium 3 "What are the stable isotopes of nitrogen yahoo dating"because deuterium has twice the mass of protium and tritium has three times the mass of protium.
These mass differences also affect the behavior of their respective chemical bonds, by changing the center of gravity reduced mass of the atomic systems. However, for heavier elements the relative mass difference between isotopes is much less, so that the mass-difference effects on chemistry are usually negligible. Heavy elements also have relatively more neutrons than lighter elements, so the ratio of the nuclear mass to the collective electronic mass is slightly greater.
Similarly, two molecules that differ only in the isotopes of their atoms isotopologues have identical electronic structure, and therefore almost indistinguishable physical and chemical properties again with deuterium and tritium being the primary exceptions. The vibrational modes of a molecule are determined by its shape and by the masses of its constituent atoms; so different isotopologues have different sets of vibrational modes. Because vibrational modes allow a molecule to absorb photons of corresponding energies, isotopologues have different optical properties in the infrared range.