<span>(C) in the nucleus with neutrons
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A compound is formed due to the chemical combination or chemical reaction between two or more elements. The elements forming a compound cannot be separated by physical means. The properties of the compound is different from the properties of the elements forming it.
Based on this, the answer would be:
They are different.
No, isotopes are versions of elements, where as ions are atoms or molecules.
<span>a regulate is to control or direct by a rule, principle, or method.</span>