Answer:
You may be referring to the gas that makes up 21% of the earth's atmosphere, which is oxygen.
Explanation:
According to NASA, the gases in Earth's atmosphere include:
Nitrogen — 78 percent
Oxygen — 21 percent
Argon — 0.93 percent
Carbon dioxide — 0.04 percent
(Trace amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor)
Half life is the time taken for a radioactive isotope to decay by half its original mass. In this case the half life of carbon-14 is 5.730 years.
Using the formula;
New mass = original mass × (1/2)^n; where n is the number of half lives (in this case n=1 )
New mass = 2 g × (1/2)^1
= 1 g
Therefore; the mass of carbon-14 that remains will be 1 g
A challenge they could face is that the plants are not used to the climate in the new area . (sorry if it’s wrong)
There are 1.48 × 10²⁵ molecules of zinc oxide in a 2 kg sample. Details about number of molecules can be found below.
<h3>How to calculate number of molecules?</h3>
The number of molecules of a substance can be calculated by multiplying the number of moles of the substance by Avogadro's number.
According to this question, there are 2000g of ZnO in a sample. Zinc oxide has a molar mass of 81.38 g/mol.
no of moles = 2000g ÷ 81.38g/mol
no of moles = 24.57mol
number of molecules = 24.57 × 6.02 × 10²³
number of molecules = 147.95 × 10²³
Therefore, there are 1.48 × 10²⁵ molecules of zinc oxide in a 2 kg sample.
Learn more about number of molecules at: brainly.com/question/11815186
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