Answer:
That the isotope H-1 is the most abundant in nature.
Explanation:
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In this case, since the average atomic mass of an element is computed considering the mass of each isotope and the percent abundance each, for hydrogen we would set up something like this:

Moreover, since the isotope notation H-1 and H-2 means that the atomic mass of H-1 is 1 amu, that of H-2 is 2 amu and the average one is 1.0079 amu, we can infer that the most of the hydrogen in nature is H-1 as the most of it composes the average hydrogen atom.
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The reaction between concentrated acid and water can release a lot of heat. If a little water is added to a larger amount of acid, the heat can cause the small amount of water to boil very rapidly which then spatters some acid. ... It is recommended that acid should be added to water and not water to acid.
Answer:
temporary changes are the changes which are there only for a short period if time.
Explanation:
generally temporary changes are reversible. permanent changes are the changes which remain for a longer time and are not reversible