Final answer:
Oxygen-16 has the highest natural abundance, while oxygen-17 has the lowest. Both oxygen-18 and oxygen-17 are non-radioactive, stable isotopes.
Step-by-step explanation:
The oxygen isotope with the highest natural abundance is oxygen-16, making up 99.759% of the oxygen found naturally. Conversely, the oxygen isotope with the lowest natural abundance is oxygen-17, which constitutes only 0.037% of naturally occurring oxygen. It is important to note that oxygen-18 is not a radioactive isotope; instead, it is a natural, stable isotope used in various scientific studies, such as paleoclimatology. Similarly, oxygen-17 is also stable and non-radioactive. Isotopes have the same number of protons, therefore all oxygen isotopes have 8 protons. The difference between the isotopes lies in the number of neutrons: oxygen-16 has 8 neutrons, oxygen-17 has 9 neutrons, and oxygen-18 has 10 neutrons.