For example, a term used in the past for contamination by radioactive isotopes was Sunshine units .< ref >

For many geologic applications, isotope ratios are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature, the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice.

For rocks dating back to the beginning of the solar system, this requires extremely long-lived parent isotopes, making measurement of such rocks ' exact ages imprecise.

For instance, uranium and thorium have no stable isotopes but occur naturally in the Earth's crust and atmosphere.

For example, according to Callen, " in absolute thermodynamic equilibrium all radioactive materials would have decayed completely and nuclear reactions would have transmuted all nuclei to the most stable isotopes.

For a list half-lives in this timescale, see: List of isotopes by half-life

For instance, the variation in the ratios of stable hydrogen isotopes across latitudes makes it possible to roughly establish the origins of migrant birds using mass spectrometric analysis of feather samples.

For example, some stable isotopes like neon-21 and neon-22 are produced in several routes of nucleogenic synthesis, and thus only part of their abundance is primordial.

For isotopes with remarkably low probability of having nuclei struck by neutrons, this seemed an apt, if amusing, analog.

For further details see commonly used gamma emitting isotopes.

For instance, one kilogram of potassium contains 0. 12 gram of < sup > 40 </ sup > K ( all other isotopes are stable ) that has a of 1. 248years = 39. 38 seconds, and has

For best result the researcher would need to know the original levels, or an estimation thereof, of isotopes in the organism at the time of its death.

For example, natural uranium is not significantly radioactive, but pitchblende, a uranium ore, is 13 times more radioactive because of the radium and other daughter isotopes it contains.

For example, the isotope effect is used so extensively to investigate chemical mechanisms and the use of cosmogenic isotopes and long-lived unstable isotopes in geology that it is best to consider much of isotopic chemistry as separate from nuclear chemistry.

For biochemical and physiological experiments and medical methods, a number of specific isotopes have important applications.

For some isotopes the half-life is so short that preparation and measurement is difficult.

For short-lived isotopes such as < sup > 11 </ sup > C, very rapid synthetic methods have been developed to permit the rapid addition of the radioactive isotope to the molecule.

For example, in 1925 the problematic chlorine was found to be composed of the isotopes Cl-35 and Cl-37, in proportions such that the average weight of natural chlorine was about 35. 45 times that of hydrogen.

For example, the incidence of < sup > 18 </ sup > O ( the heavy isotope of oxygen ) can be used as an indicator of polar ice sheet extent, and boron isotopes are key indicators of the pH and CO < sub > 2 </ sub > content of oceans in the geologic past.

For instance, we could apply survival analysis to a mixture of stable and unstable carbon isotopes ; unstable isotopes would decay sooner or later, but the stable isotopes would last indefinitely.

For example, the isotopes of hydrogen can be written as < sup > 1 </ sup > H, < sup > 2 </ sup > H and < sup > 3 </ sup > H, with the mass number at top left.

For example, a main battle tank will usually have the heaviest armour on the hull front and the turret, lighter armour on the sides of the hull and the thinnest armour on the top and bottom of the tank.

For instance, slower lighter aircraft are usually allowed closer and lower to the crowd than larger, faster types.

For centuries, viola makers have experimented with the size and shape of the viola, often adjusting the proportions or shape to make a lighter instrument with shorter string lengths, but which still has a large enough sound box to create an unmistakable ' viola sound '.

For smaller, lighter jobs, the router used in this way can be more convenient than the spindle moulder, with the task of set up being somewhat faster.

For the 1996 – 97 season, the Jazz drastically updated their logos and uniforms, with a new color scheme of purple ( slightly lighter from the previous shade ), copper and turquoise.

For the United Kingdom, the Independent Television Commission banned Springer and other tabloid talk programs from being shown on television during daytime hours on school holidays in response to numerous parental complaints and concerns about children's potential exposure to the salacious content ( there was a short-running British version of the show made for ITV called The Springer Show that was lighter and more tongue-in-cheek ).

For example, during the extraction of gold from ore, a device called a shaker table uses gravity, vibration, and flow to separate gold from lighter materials in the ore ( sorting by size and weight ).

For shorter-range work, a lighter weapon with a higher rate of fire is required, to increase a hit probability on a fast airborne target.

For example, a 50 kilo leopard can see and hear the sounds produced by a 15 kilo monkey, but as a lighter monkey can live much higher on the tree branches, it is out of reach of a heavier leopard.

For instance, in aircraft, turbine ( jet and turboprop ) engines are typically much smaller and lighter than equivalently powerful piston engine designs, both properties reducing the levels of drag on the plane and reducing the amount of power needed to move the aircraft.

For bacteria, it is more convenient for them to uptake < sup > 14 </ sup > N as opposed to < sup > 15 </ sup > N because it is a lighter element and easier to metabolize.

For air freight the alternative and lighter IATA-defined Unit Load Device is used.

For lighter weapons such as rifles, a bipod is more common.

For most of its period of production the coin weighed 16. 7-16. 8 grams and was 31-32 millimetres in diameter, although the coins of Charles II were about 0. 1 grams lighter and 1 millimetre smaller.

For this reason, lighter wheels are sought especially for high-performance applications.

For example, film producers hire lighter-skinned African Americans more often, television producers choose lighter skinned cast members, and magazine editors choose African American models that resemble European features.

For instance, the 2, 200 kW of a modern British Rail Class 66 were already met in 1927 by the electric SBB-CFF-FFS Ae 4 / 7 ( 2, 300 kW ), which is even a bit lighter.

For a lighter meal, a clam roll is made by piling clams into a hot dog bun.

For lighter AGTs, these solutions were over-specified given the size of the vehicle, so the guideway was often separate from the running surface.

For secondary routes a lighter 85BH ( 42. 16 kg per metre ) section was used.

For a given cartridge, a bolt-action rifle is cheaper to build and maintain, more reliable, and lighter, due to fewer moving parts in the mechanism.

For small crimes ( punishable by a fine or lighter punishment ) and civil suits ( involving claims not exceeding 900, 000 yen ), 448 summary courts have jurisdiction.

For example, Motorola reports that their new RoHS wireless device assembly techniques are "... enabling a smaller, thinner, lighter unit.

For example, if the other person maintains his or her bow for longer than expected ( generally about two or three seconds ), it is polite to bow again, upon which one may receive another bow in return, often leading to an exchange of progressively lighter bows.