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Having a very long half life (especially the isotope 238U) uranium remain in the earth (in the earth crust and also in the interior). The age of the earth (and also the age of the universe) is too small to permit the decay of the total quantity of uranium.
It is also important to understand exactly what is meant by half life. There can be a misconception that the half life is equal to half the time which a radioactive material will remain radioactive. This is incorrect. Instead half life can be considered as the time taken for 50% of a radioactive material to undergo radioactive decay.
It is impossible to tell exactly which atoms of the whole material sample will decay or exactly when, the only certainty is that after a length of time equal to the half life, 50% of them will have undergone decay. After another length of time equal to the half life 50% of the remaining original element will have decayed. This is an example of exponential decay. The half life of Uranium is 4.468×109 years. An illustrative example of the decay of a 1kg mass of uranium 238 is given below:
Starting with:
1kg Uranium 238
4.468×109 years pass:
0.5 kg of Uranium 238 remains, along with 0.5 kg of decay product.
A further 4.468×109 years pass leaving:
0.25 kg of Uranium 238 and 0.75 kg of assorted decay products.
Another 4.468×109 years pass leaving:
0.125 kg of Uranium 238 and 0.875 kg of assorted decay products.
Note that this span of time is approximately equal to 13.5 billion years. Which is approximately equal to the current estimates for the age of our universe as explained at the start of the answer and should help to demonstrate how uranium's long half life means it is still found in nature.
What else can I help you with?
Which element has lowest atomic number and is not found in nature?
Hydrogen has the lowest atomic number, and is not found in nature as individual atoms, but is found in nature as the diatomic molecule, H2.
Are alkali metals always found pure in nature?
Alkali metals are not found as pure elements in nature.
Were is radium found?
nature
When metalloids are found in nature they are usually in?
When metalloids are found in nature, they are usually in the form of compounds or minerals. They can be commonly found in ores such as bauxite, borax, or arsenopyrite. In their pure elemental form, metalloids are rare in nature.
What are things found in nature?
Things found in nature include rocks, trees, streams, flowers, clouds, mountains, etc.
Explain how the materials found on earth contribute to the balance of nature?
Suma
Is chlorine synthetic not found in nature or found in nature?
Not found!
Does uranium 238 have the shortest half life?
No, uranium-238 has a long half-life of about 4.5 billion years. It is a naturally occurring isotope that is commonly found in nature. Shorter-lived isotopes, such as radon-222 or polonium-214, have much shorter half-lives.
What food is blue and can be found in nature?
Blueberries are a type of food that is blue and can be found in nature.
Which element has lowest atomic number and is not found in nature?
Hydrogen has the lowest atomic number, and is not found in nature as individual atoms, but is found in nature as the diatomic molecule, H2.
Is xenon found combined in nature?
Because Xenon is a gas and gases are found uncombined in nature, Xenon is found uncombined.ct
What is the most common polysaccharide found in nature?
The most common polysaccharide found in nature is cellulose.
What is the most common metalloid found in nature?
The most common metalloid found in nature is silicon.
Are daisies wildflowers commonly found in nature?
Yes, daisies are wildflowers that are commonly found in nature.
Where boron was found in?
it was found in 1808 and it is not found free in nature
What are elements called when they are found in nature?
Elements found in nature are referred to natural elements, as opposed to synthetic, which are man made.
Is splenda found in nature?
splenda is a sucralose based artificial sweetener so by itself it is not found in nature.
