In three papers which were published in 1952 – 53, Bohr and Mottelson demonstrated close agreement between theory and experiment ; for example, showing that the energy levels of certain nuclei could be described by a rotation spectrum.

A few minutes into the expansion, when the temperature was about a billion ( one thousand million ; 10 < sup > 9 </ sup >; SI prefix giga -) kelvin and the density was about that of air, neutrons combined with protons to form the Universe's deuterium and helium nuclei in a process called Big Bang nucleosynthesis.

Although all the nuclei of all atoms belonging to one element will have the same number of protons, they may not necessarily have the same number of neutrons ; such atoms are termed isotopes.

Depending on the species, these can have one, four or eight nuclei and are variable in size ; these characteristics help in species identification.

In particle physics, a fermion ( a name coined by Paul Dirac from the surname of Enrico Fermi ) is any particle characterized by Fermi – Dirac statistics and following the Pauli exclusion principle ; fermions include all quarks and leptons, as well as any composite particle made of an odd number of these, such as all baryons and many atoms and nuclei.

There is ample evidence that the intense radiation emitted by certain kinds of astronomical objects is due to black holes ; for example, microquasars and active galactic nuclei result from the presence of stellar black holes and black holes of a much more massive type, respectively.

It is also partly responsible for the fact that the alpha particle is by far the most common type of baryonic particle to be ejected from atomic nuclei ; in other words, alpha decay is far more common than cluster decay.

Hematoxylin, a basic dye, stains nuclei blue due to an affinity to nucleic acids in the cell nucleus ; eosin, an acidic dye, stains the cytoplasm pink.

Thus, energy is no longer released when such nuclei are made by fusion ; instead, energy is absorbed in such processes.

In nuclear fission events the nuclei may break into any combination of lighter nuclei, but the most common event is not fission to equal mass nuclei of about mass 120 ; the most common event ( depending on isotope and process ) is a slightly unequal fission in which one daughter nucleus has a mass of about 90 to 100 u and the other the remaining 130 to 140 u.

For the same reason, larger nuclei ( more than about eight nucleons in diameter ) are less tightly bound per unit mass than are smaller nuclei ; breaking a large nucleus into two or more intermediate-sized nuclei, releases energy.

Models predict that the inner cloud should have tens or hundreds of times as many cometary nuclei as the outer halo ; it is seen as a possible source of new comets to resupply the relatively tenuous outer cloud as the latter's numbers are gradually depleted.

Rotations are collective motions of the atomic nuclei and typically lead to spectra in the microwave and millimeter-wave spectral regions ; rotational spectroscopy and microwave spectroscopy are synonymous.

The extremely energetic neutrinos fragment some nuclei ; some of their energy is consumed in releasing nucleons, including neutrons, and some of their energy is transformed into heat and kinetic energy, thus augmenting the shock wave started by rebound of some of the infalling material from the collapse of the core.

; Molecular dynamics: Application of classical mechanics for simulating the movement of the nuclei of an assembly of atoms and molecules.

Six lepton s and six quark s comprise most of the matter ; for example, the proton s and neutron s of atomic nucleus | atomic nuclei are composed of quarks, and the ubiquitous electron is a lepton.

The intensity of Thomson scattering declines as 1 / m < sup > 2 </ sup > with the mass m of the charged particle that is scattering the radiation ; hence, the atomic nuclei, which are thousands of times heavier than an electron, contribute negligibly to the scattered X-rays.

Grey matter is distributed at the surface of the cerebral hemispheres ( cerebral cortex ) and of the cerebellum ( cerebellar cortex ), as well as in the depths of the cerebrum ( thalamus ; hypothalamus ; subthalamus, basal ganglia-putamen, globus pallidus, nucleus accumbens ; septal nuclei ), cerebellar ( deep cerebellar nuclei-dentate nucleus, globose nucleus, emboliform nucleus, fastigial nucleus ), brainstem ( substantia nigra, red nucleus, olivary nuclei, cranial nerve nuclei ) and spinal grey matter ( anterior horn, lateral horn, posterior horn ).

Fluoride " loses " a pair of valence electrons because the electrons shared in the B — F bond are located in the region of space between the two atomic nuclei and are therefore more distant from the fluoride nucleus than they are in the lone fluoride ion.

Actinosphaerium are several times larger, from 200-1000 μm in diameter, with many nuclei, and are found exclusively in fresh water.

After about 379, 000 years the electrons and nuclei combined into atoms ( mostly hydrogen ); hence the radiation decoupled from matter and continued through space largely unimpeded.

These are processes which create compound nuclei at low excitation energy (~ 10-20 MeV, hence " cold "), leading to a higher probability of survival from fission.

The team were able to detect the alpha decay from a descendant of the 1n evaporation channel, providing some evidence for the formation of element 107 nuclei.

These are processes which create compound nuclei at high excitation energy (~ 40-50 MeV, hence " hot "), leading to a reduced probability of survival from fission and quasi-fission.

In both cases, they were unable to detect any spontaneous fission from nuclei of bohrium.

Beginning with carbon, elements are produced in stars by buildup from alpha particles ( helium nuclei ), resulting in an alternatingly-larger abundance of elements with even atomic numbers ( these are also more stable ).

Iron-56 is particularly common, since it is the most stable element that can easily be made from alpha particles ( being a product of decay of radioactive nickel-56, ultimately made from 14 helium nuclei ).

In supernova explosions, calcium is formed from the reaction of carbon with various numbers of alpha particles ( helium nuclei ), until the most common calcium isotope ( containing 10 helium nuclei ) has been synthesized.

Each isomer is a local minimum on the energy surface ( called the potential energy surface ) created from the total energy ( i. e., the electronic energy, plus the repulsion energy between the nuclei ) as a function of the coordinates of all the nuclei.

Energetically, these bands are located between the energy of the ground state, the state in which electrons are tightly bound to the atomic nuclei of the material, and the free electron energy, the latter describing the energy required for an electron to escape entirely from the material.

The core of a star is kept from collapsing by the heat generated by the fusion of nuclei of lighter elements into heavier ones.

Type Ia supernovae derive their energy from runaway fusion of the nuclei in the interior of a white dwarf.

# A biochemists ’ operational definition: Chromatin is the DNA / protein / RNA complex extracted from eukaryotic lysed interphase nuclei.

Waves of the electromagnetic spectrum vary in size, from very long radio waves the size of buildings to very short gamma rays smaller than atom nuclei.

The number of nuclei in the cyst varies from 1 to 8 among species and is one of the characteristics used to tell species apart.

It has been suggested that the radiation from bright newly formed stars, or from an active galactic nuclei can slow the contraction of a forming disk.

The (; singular: ; also ; Latin, from Greek,, ' almond ', ' tonsil ', Research like this indicates that different nuclei within the amygdala have different functions in appetitive conditioning.

The stratum corneum ( Latin for ' horned layer ') is the outermost layer of the epidermis, consisting of dead cells ( corneocytes ) that lack nuclei and organelles.

The inferior colliculus ( IC ) ( Latin, lower hill ) is the principal midbrain nucleus of the auditory pathway and receives input from several more peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex.

These nuclei, organized at the regimental level and above, were " illegal ," meaning they were formed without Nationalist knowledge or authorization.

Nuclei move from one mycelium into the other, forming a heterokaryon ( meaning " different nuclei ").

A less moderated neutron energy spectrum does worsen the capture / fission ratio for < sup > 235 </ sup > U and especially < sup > 239 </ sup > Pu, meaning that more fissile nuclei fail to fission on neutron absorption and instead capture the neutron to become a heavier nonfissile isotope, wasting one or more neutrons and increasing accumulation of heavy transuranic actinides, some of which have long half-lives.

The atoms of words holding the nuclei of original meaning he called Etyme ( etyms ).

The s process is secondary, meaning that it requires preexisting heavy isotopes as seed nuclei to be converted into other heavy nuclei.

However the meaning of matter used here relates explicitly to substances made of atoms and molecules, disregarding the matter within the atomic nuclei and its nuclear reaction or matter within highly ionized plasmas.

As development of mirror systems progressed, additional sets of magnets were added to either side, meaning that the nuclei had to escape through two such areas before leaving the reaction area entirely.

Because astrophysical plasmas are generally hot, ( meaning that they are fully ionized ), electrons in the plasmas are continually emitting X-rays through a process called bremsstrahlung, when electrons nearly collide with atomic nuclei.

Both < sup > 17 </ sup > O and < sup > 18 </ sup > O are secondary isotopes, meaning that their nucleosynthesis requires seed nuclei.

Pu-239 and Pu-241 are fissile, meaning that the nuclei of its atoms can break apart by being bombarded by slow moving thermal neutrons, releasing energy, gamma radiation and more neutrons.