Radioactive isotopes are used to
a.
determine the absolute age of rocks.
c.
determine how rocks are formed.
b.
determine the relative age of rocks.
d.
determine how rocks are changed.

A. Determine the absolute age of rocks

Explanation:

As the radioactive isotopes are used to define the age of rocks on earth these use dating techniques of C-14, isotope and thus define their absolute ages in term of mineral composition and nature of occurrences.  The absolute age of rocks tells us about various characteristics of the rocks as compared to the relative age of the rocks that is the relation of rocks with that of the other rocks in relation to the above below layers/ strata. Radioactive isotopes are also used in submarine carriers and various vessel's like nuclear reactors, igneous rocks have uranium-lead dating and potassium-argon dating.

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