Stable and unstable isotopes. Medical search. Frequent questions

Up to about 100 years ago, scientists thought that all atoms were stable like this, but many atoms come in different forms. (howstuffworks.com)
Atoms of both isotopes of copper have 29 protons, but a copper-63 atom has 34 neutrons while a copper-65 atom has 36 neutrons. (howstuffworks.com)
However, it is remarkable that neutrons, when they exist together with protons in the nucleus of atoms, are stable. (ieer.org)
They will be able to explain, understand and graph the relationships between the number of radioactive atoms versus stable atoms. (scienceteacherprogram.org)
UNSTABLE atoms (with excess energy) undergo spontaneous (look it up) breakdown into more STABLE (lower energy) forms. (scienceteacherprogram.org)
These unstable atoms are called RADIO ISOTOPES, and they break down by the process of RADIOACTIVE DECAY. (scienceteacherprogram.org)
The RADIO in these words comes from the fact that the energy they lose as they become stable is given off as RADIATION, and the atoms are said to be RADIOACTIVE. (scienceteacherprogram.org)
The STABLE DECAY PRODUCT (the new, lower energy atoms that result from the decay) is called DAUGHTER ELEMENTS. (scienceteacherprogram.org)
Muonic atoms to measure charge radii of stable and soon unstable nuclei? (psi.ch)
ray transitions in muonic atoms have been used to derive absolute charge radii of many stable nuclei. (psi.ch)
Yes, there are isotopes which would be stable if any atoms of them existed, and we can make them in the laboratory, but conditions in nature have never led to them being created. (stackexchange.com)
Nuclear reactors transform the energy released by decaying, unstable atoms into electricity. (zmescience.com)
This reaction requires unstable atoms in order to work since we'll be using that instability to break them apart and extract energy. (zmescience.com)
it is conceivable that, for a very short time period (e.g. 10ˆ-18 sec), a series of neutral mini atoms of hydrogen could be formed, in an unstable state , of various size and energy level, distributed within the Fermi band, which is enlarged due to the very short time (Heisenberg). (journal-of-nuclear-physics.com)
Nuclei of atoms of the same element that have different numbers of neutrons are different isotopes of one another. (nagwa.com)
Atoms with the same number of protons but different numbers of neutrons are called isotopes. (mysciencebox.org)
When a layer of igneous rock is laid down from a volcanic eruption, all the atoms begin as the parent isotope. (mysciencebox.org)
The word "stable" also describes atoms , and therefore substances, that do not spontaneously undergo nuclear decay, though a stable isotope may (eventually) result directly from the decay of an unstable one. (explainxkcd.com)
Because the NSCL is the nation's premier rare isotope accelerator, it's capable of shooting 100 billion krypton atoms a second. (scienceblog.com)
The stable isotopes are atoms of the same element that have extra neutrons but need not give off energy or particles to remain in balance. (examplespedia.com)
Xe-135 has such a large neutron cross-section that the vast majority of Xenon-135 atoms will never decay in a reactor - they absorb a neutron and become stable Xe-136 before they get a chance to decay. (energyfromthorium.com)

The team bombarded a target of bismuth-209 with accelerated nuclei of iron-58 and detected a single atom of the isotope meitnerium-266: 209 83Bi + 58 26Fe → 266 109Mt + n This work was confirmed three years later at the Joint Institute for Nuclear Research at Dubna (then in the Soviet Union). (wikipedia.org)
Conclusions: Extending the available data towards light unstable nuclei with a consistent set of new data has allowed a systematic investigation of the role of the excitation energy induced in projectile fragmentation. (lu.se)
Nature cherishes stable configurations and therefore the fusion process described in our last article, which brings us from hydrogen up to heavier, more stable nuclei, will not continue beyond iron-56. (scienceinschool.org)
These nuclei are just heavier isotopes of the original element, so we have not yet achieved our aim of creating a heavier, different element. (scienceinschool.org)
The nuclei of some elements are not stable. (ieer.org)
Presently, the obtained radii, together with those provided by electron scattering, are used extensively as input to connect the optical isotope shifts with changes in charge radii for radioactive nuclei. (psi.ch)
Laser spectroscopy on radioactive nuclei which provides these optical isotope shifts is at present a very active field (3 setups at CERN-ISOLDE alone) and thus many radii of stable nuclei are used every year as calibrations. (psi.ch)
[a] One of its isotopes, 270 Hs, has magic numbers of both protons and neutrons for deformed nuclei, which gives it greater stability against spontaneous fission . (wikipedia.org)
This decreased the number of neutron ejections during synthesis, creating heavier, more stable resulting nuclei. (wikipedia.org)
Stable Transuranics are usually classified as superheavy nuclei with proton numbers greater than 112 and half lives of at least one year, though precise definitions and naming conventions tend to vary between different polities. (orionsarm.com)
Early techniques included scavenging useful products of radioactive decay or neutron transmutation from the waste of fission power plants, and the bombarding of heavy nuclei in particle accelerators to create (generally unstable and very short lived) novel nuclei by fusion. (orionsarm.com)
The radioactive isotopes are altered over time, emitting radiation in the form of alpha rays (helium nuclei), beta rays (electrons or positrons energy and speed) or gamma (high frequency energy of the electromagnetic spectrum). (examplespedia.com)
All nuclei can be given a position in a nu- clear chart based on their number of neutrons, N and protons, Z. The light stable nuclei follow the line of stability, where N Z. Heavier nuclei tend to have more neutrons than protons, to damp out the increasing electrostatic repulsion between the protons, i.e to be stable. (lu.se)
Nuclei on both sides of the line of stability exist, but they are unstable and they will decay towards the line of stability. (lu.se)
Through experiments it was discovered that nuclei having certain numbers of protons and neutrons are more stable than their neighbors on the nuclidic chart. (lu.se)

Radioactive forms of cesium are unstable and eventually change into other more stable elements through the process of radioactive decay. (cdc.gov)
Unstable isotopes generally undergo transmutation, alpha decay or beta decay. (brightstorm.com)
If the neutron capture produces an unstable isotope, then it can undergo a spontaneous radioactive decay. (scienceinschool.org)
In other words, as soon as the first unstable configuration is reached, a beta decay turns the nucleus into one with one more proton and one fewer neutron (see diagram below ). (scienceinschool.org)
Free neutrons are unstable particles which decay naturally into a proton and electron, with a half-life of about 12 minutes. (ieer.org)
If a certain radioactive element, say Potassium 40 (written K 40 ), is incorporated into a crystal of K-Feldspar, it will decay, over time, to the stable element Argon 40 (written Ar 40 ). (scienceteacherprogram.org)
Isotopes of various elements decay at different rates, but they all follow a similar pattern of decay. (scienceteacherprogram.org)
The Skittles that land S - up we ll consider to be RADIOACTIVE, and the S - down Skittles are a safe stable decay product. (scienceteacherprogram.org)
As Carbon 14 is unstable, it disintegrates or goes through radioactive decay. (differencebetween.net)
Unstable or radioactive isotopes (also called radioisotopes) change structure and emit radiation spontaneously as they decay, and become different isotopes. (usgs.gov)
Spectral gamma borehole geophysical methods measure natural-gamma energy spectra, which are caused by the decay of uranium, thorium, potassium-40, and anthropogenic radioactive isotopes. (usgs.gov)
The difference is that inside the unstable copper nucleus, produced from the fusion of a hydrogen mini-atom with a nickel nucleus, is trapped the mini-atom electron ( β- ), which in my opinion undergoes in-situ annihilation, with the predicted (Focardi-Rossi) decay β+ of the new copper nucleus. (journal-of-nuclear-physics.com)
Even if we have an unstable nucleus and we suspect that at some point it will decay, it's impossible to predict when this decay will take place. (nagwa.com)
Each parent isotope has a specific rate of decay that can be precisely timed. (mysciencebox.org)
Some parent isotopes, like uranium-238 take an extremely long time to decay to the daughter isotope lead-206 (4.5 billion years for half of the uranium-238 in a given rock to decay to lead-206). (mysciencebox.org)
That's always been a missing piece of the puzzle, since the progressive decay of isotopes results in the synthesis of precious metals in exploding stars. (scienceblog.com)
Because a free neutron is slightly less stable than a free proton, neutrons beta decay to protons plus electrons plus neutrinos with a half-life of approximately 17 minutes. (evcforum.net)
The radioactive decay can produce a stable nuclide or will sometimes produce a new unstable radionuclide which may undergo further decay. (wikipedia.org)
In theory, only 146 of them are stable, and the other 105 are believed to decay via alpha decay , beta decay , double beta decay , electron capture , or double electron capture . (wikipedia.org)
detection of this decay meant that bismuth was no longer considered stable. (wikipedia.org)

To lose its excitation energy and reach a more stable state, a compound nucleus either fissions or ejects one or several neutrons, which carry away the energy. (wikipedia.org)
We recommend introducing this simulation after first exploring a related PhET simulation, "Isotopes and Atomic Mass". Beginning learners need a foundation to understand factors that affect stability of an atomic nucleus. (compadre.org)
We're going to talk about nucleus stability and what makes something stable and what makes something a nuc- a nucleus unstable. (brightstorm.com)
So the nucleus, the neutrons also help keep the [IB] nucleus together so because we're talking about this balance between electrostatic forces that are keeping them apart and then and then the strong nuclear force is keeping them together we have to have a good ratio of neutrons to protons a stable ratio. (brightstorm.com)
If this ratio gets off balance that's when the nuc- the nucleus becomes unstable and they're also emitting particles so when this ratio [IB] in a good place. (brightstorm.com)
Iron-56 has the most stable nucleus because it has the maximum nuclear binding energy (see box and diagram below ). (scienceinschool.org)
Each neutron capture in the s-process converts a nucleus to an isotope of the same element with one more neutron. (scienceinschool.org)
Because the neutron capture is relatively slow in the s-process, the unstable nucleus beta-decays before any more neutrons can be captured. (scienceinschool.org)
The processes of transformation of one isotope to another may leave the resulting nucleus with an excess of energy, which may be emitted as electromagnetic radiation in the form of gamma photons or gamma rays. (usgs.gov)
An unstable nucleus sheds vitality in order that it could shift to a more stable configuration. (groundzeroprojects.com)
The mechanism proposed by Focardi - Rossi, verified by mass spectroscopy data, which predicts transmutation of a nickel nucleus to an unstable copper nucleus (isotope), remains in principle valid. (journal-of-nuclear-physics.com)
The β+ and β- annihilation (interaction of matter and anti-matter) would lead to the emission of a high energy photon, γ , (Einstein) from the nucleus of the now stable copper isotope and a neutrin to conserve the lepton number. (journal-of-nuclear-physics.com)
Both of these forces are needed for the nucleus to be balanced and stable. (nagwa.com)
We've seen that the number of protons and neutrons in the nucleus tells us which element that atom is as well as the isotope of that element. (nagwa.com)
When a nucleus is stable, when all the forces acting on it balance out, that means the number of protons and neutrons in the nucleus does not change. (nagwa.com)
If the forces on the particles in a nucleus do not balance out, however, that nucleus is unstable. (nagwa.com)
An unstable nucleus is one where the number of protons and neutrons can change. (nagwa.com)
An unstable nucleus may at some point break apart. (nagwa.com)
Imagine we have an unstable nucleus. (nagwa.com)
Over time, an unstable parent isotope will spontaneously eject parts of its nucleus and transform into a far more stable daughter isotope. (mysciencebox.org)
The higher the binding energy the more stable is the nucleus. (lu.se)

A fissile isotope , such as uranium-235 , is one that is sufficiently large and unstable to undergo such a chain reaction, as opposed to the more common and less unstable uranium-238 . (explainxkcd.com)

The half lives of several radio isotopes are given in your Reference Tables. (scienceteacherprogram.org)
6 ] No one knows how many abandoned vials of radio-isotopes litter the globe. (ccnr.org)
Reactors and radio-isotopes are both parts of the nuclear fuel cycle. (ccnr.org)

Isotopes can be stable or they can be unstable and emit ionised radiation when disintegrating. (dtu.dk)
How do you know of an atom or a particle is actually going to emit and be unstable enough to emit some alpha particles, gamma particles or beta particles. (brightstorm.com)

Nuclear stability is what makes certain isotopes radioactive. (brightstorm.com)
An isotope is unstable if it has a ratio of protons to neutrons that isn t within what is called the band of stability. (brightstorm.com)
Some Hider groups value the long term stability of certain transuranics and the ease with which they may be transmuted into fissile isotopes as a power source which compares favourably with many kinds of primitive antimatter storage. (orionsarm.com)
The lightest stable isotope of germanium is 70Ge, and thus 62Ge is far from stability. (lu.se)

Aluminum-27 is therefore called a stable atom. (howstuffworks.com)
The different layouts an atom can take are known as its isotopes . (zmescience.com)
An experimental collaboration at the fragment separator of the GSI Helmholtzzentrum für Schwerionenforschung has for the first time detected potassium-31, an isotope with eight neutrons less than the stable potassium atom. (gsi.de)
In isotopes, these give the atom a greater atomic mass (A), a property that is calculated with protons and neutrons. (examplespedia.com)

The principles essential to the interpretation of gamma, gamma-spectrometry, gamma-gamma, and various types of neutron logs include the nature of subatomic particles and the particles and photons emitted by unstable isotopes. (usgs.gov)
We call them "unstable" because they need to remove these neutrons and/or other subatomic particles in order to revert to 'stable' atomic layouts. (zmescience.com)
Fission starts with subatomic particles ejected from these radioactive isotopes in an effort to become stable. (zmescience.com)
Polonium is a rare and highly radioactive element with no stable isotopes, chemically similar to bismuth and tellurium, it occurs in uranium ores with applications including heaters in space probes, antistatic devices, and sources of neutrons and alpha particles. (centraldatacore.com)

if they do not get too many fissile raspberry isotopes. (explainxkcd.com)

A radionuclide ( radioactive nuclide , radioisotope or radioactive isotope ) is a nuclide that has excess nuclear energy, making it unstable. (wikipedia.org)
A radionuclide is an unstable isotope that becomes more stable by releasing energy. (msdmanuals.com)

Radioactive isotopes are constantly decaying or changing into different isotopes by giving off radiation. (cdc.gov)
In contrast, less stable stars can vary a lot in their radiation output. (skepticalscience.com)
First Singularity and modosophont industrial bases continue to make use of transuranics to this day, often for radiation shielding but also with highly stable forms (with half-lives generally measured in centuries or millenia) used for compact counterweights, gyroscopes and flywheels in devices of all sizes from synsects to interstellar vehicles. (orionsarm.com)
Micromechanical and nanomechanical components using stable transuranics are not used in high radiation environments due to their large neutron-absorption cross-sections, but are common elsewhere. (orionsarm.com)

1,130 of these are unstable, although only 65 unstable isotopes occur naturally. (usgs.gov)
Seven other elements were first created artificially and thus considered synthetic, but later discovered to exist naturally (in trace quantities) as well' - they say that the 24 elements are all unstable, whereas the other 7 occur in nature. (stackexchange.com)
Radioactive isotopes are naturally occurring, but they're very rare. (zmescience.com)

In theory, elements heavier than dysprosium exist only as radionuclides, but some such elements, like gold and platinum , are observationally stable and their half-lives have not been determined). (wikipedia.org)
Also called radiocarbon, carbon-14 is a slightly heavier version of the stable element carbon, or carbon-12. (jstor.org)

The 28 protons and 50 neutrons are more stable and less reactive when they're penned up. (scienceblog.com)

The Hevesy Laboratory is part of DTU Health Tech and explores, develops and produces radioactive isotopes and radioactive medicine used for diagnosing and treating a long list of diseases, which beside cancer includes heart and brain diseases. (dtu.dk)
Researchers produce radioactive isotopes by using a biomedical cyclotron, which is placed in the basement of the Hevesy Laboratory. (dtu.dk)
This information is like gold," said Eric Foto, head of the isotope hydrology laboratory at the University of Bangui in the Central African Republic. (iaea.org)
By reproducing the processes inside supernovas in a laboratory, scientists have resurrected an isotope of nickel - one that no longer exists in nature, but is an important link in the birth of the elements. (scienceblog.com)

The fact that Xenon-135 decays and that it absorbs neutrons as it is irradiated means that when a reactor is shut down or brought to low power, it can be very unstable and the characteristics change as Xe-135 decays. (energyfromthorium.com)
Carbon-14 is unstable and decays over time. (jstor.org)

The part that scientists didn't understand until about 100 years ago is that certain elements have isotopes that are radioactive. (howstuffworks.com)
In some elements, all of the isotopes are radioactive. (howstuffworks.com)
Tin 119 Metal is one of over 250 stable metallic isotopes produced by American Elements for biological and biomedical labeling, as target materials and other applications. (americanelements.com)
Chemical elements exist in many forms called isotopes. (dtu.dk)
Elements with atomic numbers greater than 70 are never stable. (brightstorm.com)
All elements have at least some isotopes that are radioactive. (ieer.org)
All isotopes of heavy elements with mass numbers greater than 206 and atomic numbers greater than 83 are radioactive. (ieer.org)
Information about number of known elements and isotopes was accurate at the time of original publication (1990). (usgs.gov)
As far as I know, all elements without data on natural abundance there are unstable. (stackexchange.com)
That Wikipedia article talks about elements, not isotopes, so it doesn't really touch the question. (stackexchange.com)
begingroup$ @MartinKochanski: Technically, yes, this quote does not fully eliminate stable isotopes not occurring in nature (although it does touch the question, at least in the part related to the 24 synthetic elements not occurring in nature: if an element is unstable, that means all its isotopes are unstable). (stackexchange.com)
Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with nonzero quantum numbers. (iupac.org)
Scientists went further into the region of unstable elements than ever before. (gsi.de)
Examples of elements that are very stable include tin, iron, and oxygen. (nagwa.com)
Unstable elements include uranium and plutonium. (nagwa.com)
Stable transuranic elements have not been found in nature, and must be synthesised. (orionsarm.com)

Scientists study the different isotopes present in water to determine various factors and processes, including its source, age, recharge flow and quality (see Isotope hydrology ). (iaea.org)
A collaboration of scientists from the United States and Germany at the NSCL recreated Ni-78 by whirling around a stable isotope of krypton gas until it reached high speeds and then firing it into a plate of beryllium metal. (scienceblog.com)
Scientists found a similar signal in beryllium isotopes present in Antarctic ice cores . (jstor.org)

Caffeine and 14 of its metabolites are quantified in urine by use of high-performance liquid chromatography-electrospray ionization-tandem quadrupole mass spectrometry (HPLC-ESI-MS/MS) with stable isotope labeled internal standards. (cdc.gov)
Isotopes of a given element have the same chemical characteristics but a different mass. (usgs.gov)
The half - life is the parameter indicating the time it takes to disintegrate half of the mass of a radioactive isotope. (examplespedia.com)

For example, copper has two stable forms: copper-63 (making up about 70 percent of all natural copper) and copper-65 (making up about 30 percent). (howstuffworks.com)

The end goal is to concentrate the unstable isotopes in a single place, and the final product is considered to be "enriched", as in the "enriched uranium" used for fission. (zmescience.com)
Some specialist spacecraft , vecs and even cyborgs may use less stable isotopes as power sources for radioisotope thermal generators, fission rockets and very small fission reactors. (orionsarm.com)
Military use of stable transuranics is much rarer since the Golden Age, given the relative ease with which compact laser-triggered fusion devices and antimatter-catalysed fission and fusion explosives can be made or obtained. (orionsarm.com)
Ponytail fear that her raspberries have too many unstable isotopes so that her fields risk undergoing a similar fission-driven chain reaction. (explainxkcd.com)

The isotope Strontium-82 is used for cardiac imaging via Positron Emission Tomography (PET) at hospitals nationwide. (lanl.gov)

In the case of g-factor measurements of the electron bound in hydrogen-like ions by using a single ion confined in a Penning trap a comparison of the experimental value with the state-of-the-art theoretical value, which includes nuclear structure corrections, allows for a determination of the nuclear charge radius of the isotope of interest. (psi.ch)

it is a man-made element whose isotopes Am-237 through Am-246 are all radioactive. (cdc.gov)
The dripline defines the boundary between stable and unstable isotopes of a given element. (aps.org)
Measurements at next-generation rare-isotope facilities, planned to start running in two years, could extend the dripline to magnesium, the 12th element in the periodic table. (aps.org)
When we find the crystal and measure the amount of the radio isotope K 40 and the daughter element Ar 40 , we know that if there s a lot of K 40 and not much Ar 40 that the sample has not been around long enough for much K 40 to have decayed - the sample is young! (scienceteacherprogram.org)
C) On the third graph, plot the ratio of isotope to daughter element as a function of half life. (scienceteacherprogram.org)
According to https://en.wikipedia.org/wiki/Synthetic_element , all stable isotopes created artificially can also be found in nature (I don't have a more reliable source). (stackexchange.com)
EDIT(06/07/2016): see also the table of natural abundance of stable nuclides at https://www.ncsu.edu/chemistry/msf/pdf/IsotopicMass_NaturalAbundance.pdf (if an element does not have stable nuclides, they give data for the longest-living isotope). (stackexchange.com)
The number of neutrons tells us what is called the isotope of that element. (nagwa.com)
The same element can have several isotopes at the same time. (examplespedia.com)

For comparison, there are about 251 stable nuclides . (wikipedia.org)
Radionuclides are produced in stellar nucleosynthesis and supernova explosions along with stable nuclides. (wikipedia.org)

Are there stable isotopes which do not occur in nature? (stackexchange.com)

Researchers at MSU haven't been the first to find Ni-78, but they've produced 11 occurrences of the isotopes, enough to finally derive its life span, said Paul Hosmer, a doctoral candidate working on the project. (scienceblog.com)
Still, its signal is strong enough for researchers to distinguish radiocarbon from stable carbon in organic remains such as tree rings. (jstor.org)

Natural titanium consists of five isotopes with atomic masses from 46 to 50. (lanl.gov)

However, it was suggested that a so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like ions of the same isotope can be used to cancel nuclear structure effects and provide an accurate test of QED [Shabaev et al. (fnal.gov)

Carbon 12 is stable because it contains the same number of protons and neutrons and the Carbon 14 is unstable because there of the difference in their proton and neutron numbers. (differencebetween.net)

Stable isotopes are those that do not change structure or energy over time. (usgs.gov)
It is mentioned that the pies were shelf stable , which means it can last a long time without being in a refrigerator. (explainxkcd.com)

Natural strontium is a mixture of four stable isotopes. (lanl.gov)
The mixture is incubated for at least 30 min at room temperature, facilitating the conversion of an unstable uracil metabolite into a more stable form. (cdc.gov)

The isotope - nickel-78, or Ni-78 - shows up with the standard number of 28 protons, but with 50 neutrons. (scienceblog.com)
Because nickel must get rid of so many extra neutrons, this isotope is extremely unstable and does not exist in nature. (scienceblog.com)

Method: We have measured projectile fragments from C10,12-18 and B10-15 isotopes colliding with a carbon target. (lu.se)
Carbon 12 and Carbon 14 are isotopes of Carbon. (differencebetween.net)
Of these two isotopes, Carbon 12 is most abundant. (differencebetween.net)
When comparing the two isotopes, Carbon 14 is rare. (differencebetween.net)
Another thing that can be seen is that Carbon 12 is a stable isotope and Carbon 14 is an unstable isotope. (differencebetween.net)
3. Carbon 12 is a stable isotope and Carbon 14 is an unstable isotope. (differencebetween.net)
This isotope accounts for around one part in one trillion of the carbon moving through the global carbon cycle. (jstor.org)

Collinear laser spectroscopy provides access to nuclear ground-state properties via the hyperfine structure (including the isotope shift) of atomic spectra. (psi.ch)

Well when I put a ratio of the neutrons on top of the protons it's 124 to 82 which then ends up to 1, 1.51 over 1 so the ratio was 1.5 this is a large atomic number that's okay this is actually stable one this is a maximum that it can be, if this was 208, then we start going under nuclear we have a nuclear reaction. (brightstorm.com)

4. If a sample contains about 40% of its original isotope content, how many half lives old is it? (scienceteacherprogram.org)
All are unstable, decaying with half-lives ranging from 15.6 million years to a few hundred microseconds. (stackexchange.com)

We explain that what are examples of isotopes? (examplespedia.com)

And because changes in charge radii are very small, it is important that the reference radii of stable isotopes, or at least their differences, are very precise and free of large systematic errors. (psi.ch)
these isotopes can be separated by differences in their weight. (usgs.gov)

The validation of the stable island theories was heralded as the dawn of a new era of physics and chemistry. (orionsarm.com)

B) On the second graph, plot the Percent of Isotope remaining as a function of half life. (scienceteacherprogram.org)

Natural cesium is present in the environment in only one stable form, as the isotope 133 Cs. (cdc.gov)

That the Sun is a stable type of star is clearly demonstrated by the amount of Solar energy reaching Earth's average orbital position: it varies very little at all. (skepticalscience.com)
Some isotopes are used to produce nuclear energy. (examplespedia.com)

Anatomy11

Organisms13

Diseases2

Chemicals and Drugs88

Analytical, Diagnostic and Therapeutic Techniques and Equipment45

Psychiatry and Psychology3

Phenomena and Processes71

Disciplines and Occupations8

Anthropology, Education, Sociology and Social Phenomena6

Technology, Industry, Agriculture1

Humanities1

Information Science6

Health Care18

Geographicals2

Atoms21

Nuclei15

Decay20

Nucleus21

Undergo1

Radio isotopes3

Emit2

Stability4

Atom4

Particles4

Fissile1

Radionuclide2

Radiation4

Naturally3

Heavier2

Neutrons are more stable1

Laboratory4

Decays2

Elements16

Scientists3

Mass3

Copper1

Fission4

Positron Emission T1

Theoretical1

Element9

Nuclides2

Occur1

Researchers2

Consists1

Hydrogen1

Proton1

Time2

Mixture2

Nickel2

Carbon7

Shift1

Ratio1

Half lives2

Explain1

Differences2

Chemistry1

Percent1

Present1

Energy2