Isotopes are: A. are only theoretical. B. only formed in laboratories. C. found in nature. D. found in the nuclear reactions in stars but not on Earth.

An isotope is one of two or more forms of the same chemical element. Different isotopes of an element have the same number of protons in the nucleus, giving them the same atomic number, but a different number of neutrons giving each elemental isotope a different atomic weight.

Hydrogen is the most abundant element on the periodic table..hope it .

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.