Why does the proportion of isotopes in naturally occurring elemental or compound species remain almo

This in itself is a phenomenon of nature. This ratio is a fixed value for a certain period of time. This value reflects the balance of decay between isotopes of a class of elements in nature.

Just like a chemical reaction that reaches equilibrium under a system, as long as the system conditions remain unchanged, the proportion of each component in the chemical reaction that reaches equilibrium is a fixed value, or the ratio between the number of molecules participating in the reaction is a fixed value. Only now it is not a chemical reaction, but a nuclear physical process - decay. You can also draw an analogy to the ratio of various blood types in a population of the same ethnicity.

This is another equilibrium, another law, which is determined by genes.

Naturally occurring isotopes that maintain a certain ratio with each other. The relative atomic mass of an element is the average value calculated from a certain percentage of the atoms of the various nuclides of the element.

Boron has two natural isotopes 10-5b 11-5b, where the mass fraction of 10-5b in the boron element is. Then what is the relative atomic mass of boron?

Let 1mol b contain x mol 10-5 b and (1-x) mol 11-5b:

then its molar mass = 10x + 11(1-x) = 11-x100% *10x(11-x) =

x=, then the relative atomic mass of the boron element is =

Because there will be other elements that decay and transform into elements like them.

Summary. Hello, if two atoms have the same number of protons, but the number of neutrons is different, they still have the same atomic order and are the same position elements in the periodic table.

Hello, if two atoms have the same number of protons, but the number of neutrons is different, they still have the same atomic order and are the same position elements in the periodic table.

What about isotope distribution?

Hello, the relative and absolute abundance of isotope distributions. The general trend of distribution is similar, with some significant variations.

What does isotope distribution refer to in the same compound?

Hello, in the same compound, the isotope is two nuclides with the same number of protons and different neutron numbers, belonging to different manifestations of the same element, strictly speaking, not the same substance, but the physical properties are the same, the chemical properties are slightly different, and it is used in biology to label elements to track the transformation of this element in the body.

The isotopes have similar physical and chemical properties and are homogeneously mixed in nature. It's like solvents and solutes. No matter how you take it. The percentages are the same.

It's just a statistical law ... If you know the law of large numbers in statistics, when the number of people is small, the ratio of men to women may deviate greatly from one to one, but if there are many people, the ratio of men and women in the world is infinitely close to one to one. Because the number of atoms contained in a chemical substance is quite large and measured in moles, it satisfies the law of large numbers in its distribution, that is, the proportion of different isotopes is constant.

Multiplying the atomic weight of various isotopes by their weight in nature gives the average atomic mass, like chlorine, which is the average atomic mass, which is the combined average of the two isotopes Cl35 and Cl37.

The abundance of elements on Earth, including the abundance of different isotopes, is largely determined by the elemental composition of the pre-solar nebula that formed the solar system. With the exception of hydrogen and helium, all heavy elements are produced by nuclear reactions inside pre-existing stars, which in a short period of time eject large amounts of material in the form of superstar explosions, and these materials form nebulae that are relatively homogeneous in composition. The solar system was born from such a relatively homogeneous nebula.

Chemical changes do not alter isotope abundance, and with the exception of radioactive decay of some isotopes, the surface does not have the conditions for a natural nuclear reaction. Therefore, the abundance of naturally occurring isotopes on the surface is generally stable. However, some primitive meteorites may contain particulate matter that did not undergo the homogenization process during the formation of the solar system, and its elemental abundance and natural abundance are greatly deviated.

It is in this proportion that it is reflected.

The so-called ratio, also known as abundance, refers to the natural proportion of the various isotope content of a certain element in nature.

For example, C has C12 and C14, and these two isotopes are different only in terms of neutron number, and the rest are the same, so the chemical properties are exactly the same.

Although a large number of chemical reactions involving lead and carbon occur on the earth every day, since there is no effect on the number of neutrons, there is no effect on the proportion of isotopes in either elemental or chemical states.

That is, the abundance does not change over a long period of time.

The answer is wrong because the relative atomic mass is 152, then according to the number of protons, it can be seen that its average neutron number is 89, so it is impossible to have an atom with a neutron number of 89, otherwise the average neutron number of the two isotopes cannot reach 89

Natural isotopes refer to the existence (i.e., not artificial) of the same element (proton number, etc.) in nature (i.e., not artificially made) with multiple nuclides (except for potassium, which has only one), for example, there are three natural isotopes of oxygen, two natural isotopes of boron, and two natural isotopes of copper......

Although a large number of chemical reactions involving carbon occur on Earth every day, they have no effect on the proportion of isotopes because they have no effect on the number of neutrons, whether they are elemental or combined. That is, the percentage (abundance) of the number of atoms of each isotope in nature does not change for a long time.

Method for determining the percentage of the number of atoms of each isotope: (take a certain amount of gas (this is actually needless to say 0))1Infrared spectroscopy 2Ionization mass spectrometer 3Plasma mass spectrometry, etc.

In the naturally occurring Jingshu certain elements, whether free or combined, various isotopes.

The percentage of atoms is generally constant. This should refer to isotope abundance: the relative content (in atomic percentages) of the various isolimb isotopes of an element present in natureNumber of 18o o Number of all isotopes = , chemical reaction.

did not change its nucleus.

structure. Whether in the free state or the chemical state, what changes is the electronic structure outside the nucleus of the atom, but the nucleus does not change, that is to say, the number of protons does not change (the atomic number does not change), and the number of neutrons does not change (the specific isotope is also determined), so the existence of isotopes is not affected by the state of the atom, for example, oxygen 18 atoms, if it is in oxygen molecules, it is also oxygen 18, and in heavy oxygen water, it is also oxygen 18 atoms. For example, oxygen 18 is an oxygen-producing element on the earth's crust.

The ratio of all isotopes is 18o = the abundance of oxygen 18).