This-is-because-sup-238-sup-U-is-much-mor

This is because 238 U is much more stable than 235 U or 234 U, as the half-life of each isotope reveals: 4. 468 × 10 9 years for 238 U compared to 7. 038 × 10 8 years for 235 U and 245, 500 years for 234 U. However, the natural abundance of a given isotope is also affected by the probability of its creation in nucleosynthesis ( as in the case of samarium ; radioactive 147 Sm and 148 Sm are much more abundant than stable 144 Sm ) and by production of a given isotope by natural radioactive isotopes ( as in the case of radiogenic isotopes of lead ).

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is and because

This is puzzling to an outsider conscious of the classic tradition of liberalism, because it is clear that these Democrats who are left-of-center are at opposite poles from the liberal Jefferson, who held that the best government was the least government.

In fact it has caused us to give serious thought to moving our residence south, because it is not easy for the most objective Southerner to sit calmly by when his host is telling a roomful of people that the only way to deal with Southerners who oppose integration is to send in troops and shoot the bastards down.

Had the situation been reversed, had, for instance, England been the enemy in 1898 because of issues of concern chiefly to New England, there is little doubt that large numbers of Southerners would have happily put on their old Confederate uniforms to fight as allies of Britain.

But it is more than irony: one of the main reasons why nationalism is no longer a tenable concept is because it has spread throughout the planet.

The `` approximate '' is important, because even after the order of the work has been established by the chance method, the result is not inviolable.

Often it is recognized that all the details of the pattern may not be essential to the outcome but, because the pattern was empirically determined and not developed through theoretical understanding, one is never quite certain which behavior elements are effective, and the whole pattern becomes ritualized.

Yet often fear persists because, even with the most rigid ritual, one is never quite free from the uneasy feeling that one might make some mistake or that in every previous execution one had been unaware of the really decisive act.

Or is it relevant because it teaches us something useful to know about ourselves??

I knew that a conversation with the author would not settle such questions, because a man is not the same as his writing: in the last analysis, the questions had to be settled by the work itself.

I suggested that one must let it in because it is the truth, but Beckett did not take to the word truth.

That is why the form itself becomes a preoccupation, because it exists as a problem separate from the material it accommodates.

It is because there is not only darkness but also light that our situation becomes inexplicable.

If they avoid the use of the pungent, outlawed four-letter word it is because it is taboo ; ;

Jazz is good not only because it promotes wholeness but because of its decided sexual effect.

It is worth dwelling in some detail on the crisis of this story, because it brings together a number of characteristic elements and makes of them a curious, riddling compound obscurely but centrally significant for Mann's work.

is and <

* If it is required to use a single number X as an estimate for the value of numbers, then the arithmetic mean does this best, in the sense of minimizing the sum of squares ( x i − X )< sup > 2 </ sup > of the residuals.

When there are only two means to compare, the t-test and the ANOVA F-test are equivalent ; the relation between ANOVA and t is given by F = t < sup > 2 </ sup >.

The number of carbon atoms is used to define the size of the alkane ( e. g., C 2 - alkane ).

The simplest possible alkane ( the parent molecule ) is methane, CH 4 .

The reason why pHs of acids are less than 7 is that the concentration of hydronium ions is greater than 10 < sup >− 7 </ sup > moles per liter.

An Arrhenius acid is a substance that increases the concentration of the hydronium ion, H 3 O < sup >+</ sup >, when dissolved in water.

BF 3 is a Lewis acid because it accepts the electron pair from fluoride.

The species that gains the electron pair is the Lewis acid ; for example, the oxygen atom in H 3 O < sup >+</ sup > gains a pair of electrons when one of the H — O bonds is broken and the electrons shared in the bond become localized on oxygen.

The Brønsted-Lowry definition is the most widely used definition ; unless otherwise specified acid-base reactions are assumed to involve the transfer of a proton ( H < sup >+</ sup >) from an acid to a base.

Reactions of acids are often generalized in the form HA H < sup >+</ sup > + A < sup >−</ sup >, where HA represents the acid and A < sup >−</ sup > is the conjugate base.

The acid dissociation constant K a is generally used in the context of acid-base reactions.

The numerical value of K a is equal to the concentration of the products divided by the concentration of the reactants, where the reactant is the acid ( HA ) and the products are the conjugate base and H < sup >+</ sup >.

Because the range of possible values for K a spans many orders of magnitude, a more manageable constant, pK a is more frequently used, where pK a

is and sup

A number of non-Greek etymologies have been suggested for the name, The form Apaliunas ( d ) is attested as a god of Wilusa in a treaty between Alaksandu of Wilusa and the Hittite great king Muwatalli II ca 1280 BCE.

is and >

* cyclic ( general formula, n > 2 ) wherein the carbon backbone is linked so as to form a loop.

is and 238

* In PS 238, Atlas is a famous superhero and the father of one of the main characters

* 238 – Gordian II loses the Battle of Carthage against the Numidian forces loyal to Maximinus Thrax and is killed.

Curium is used in production of heavier actinides and of the < sup > 238 </ sup > Pu radionuclide for power sources in artificial pacemakers.

In physics, cryogenics is the study of the production of very low temperature ( below − 150 ° C, − 238 ° F or 123 K ) and the behavior of materials at those temperatures.

Shepherd Moons is also her longest charting album to date, spending 238 weeks on the Billboard 200.

The first incursion of the Roman Empire that can be attributed to Goths is the sack of Histria in 238.

*< sup > 237 </ sup > U is also produced via an ( n, 2n ) reaction with < sup > 238 </ sup > U. This only happens with very energetic neutrons.

< sup > 237 </ sup > Np is irradiated with neutrons to create < sup > 238 </ sup > Pu, an alpha emitter for radioisotope thermal generators for spacecraft and military applications.

For example, < sup > 238 </ sup > U, the most abundant form of uranium, is fissionable but not fissile: it undergoes induced fission when impacted by an energetic neutron with over 1 MeV of kinetic energy.

However, too few of the neutrons produced by < sup > 238 </ sup > U fission are energetic enough to induce further fissions in < sup > 238 </ sup > U, so no chain reaction is possible with this isotope.

Instead, bombarding < sup > 238 </ sup > U with slow neutrons causes it to absorb them ( becoming < sup > 239 </ sup > U ) and decay by beta emission to < sup > 239 </ sup > Np which then decays again by the same process to < sup > 239 </ sup > Pu ; that process is used to manufacture < sup > 239 </ sup > Pu in breeder reactors.

Bombarding < sup > 238 </ sup > U with fast neutrons induces fissions, releasing energy as long as the external neutron source is present.

This is an important effect in all reactors where fast neutrons from the fissile isotope can cause the fission of nearby < sup > 238 </ sup > U nuclei, which means that some small part of the < sup > 238 </ sup > U is " burned-up " in all nuclear fuels, especially in fast breeder reactors that operate with higher-energy neutrons.

That same fast-fission effect is used to augment the energy released by modern thermonuclear weapons, by jacketing the weapon with < sup > 238 </ sup > U to react with neutrons released by nuclear fusion at the center of the device.

Breeder reactors are a specialized form of research reactor, with the caveat that the sample being irradiated is usually the fuel itself, a mixture of < sup > 238 </ sup > U and < sup > 235 </ sup > U.

< sup > 210 </ sup > Po ( in common with < sup > 238 </ sup > Pu ) has the ability to become airborne with ease: if a sample is heated in air to 55 ° C ( 131 ° F ), 50 % of it is vaporized in 45 hours, even though the melting point of polonium is 254 ° C ( 489 ° F ) and its boiling point is 962 ° C ( 1763 ° F ).< ref >

With an area of 238, 400 square kilometers, Romania is the twelfth largest country in Europe.

The use of wind power is increasing at an annual rate of 20 %, with a worldwide installed capacity of 238, 000 megawatts ( MW ) at the end of 2011, and is widely used in Europe, Asia, and the United States.

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