Final answer:
Gallium has two naturally occurring isotopes: gallium-69 and gallium-71, which have relative natural abundances of about 60.1% and 39.9%, respectively.
Step-by-step explanation:
The naturally occurring isotopes of gallium are gallium-69 and gallium-71. Gallium, with the atomic number 31, has these two stable isotopes which are found naturally on Earth. The isotope gallium-69 has an abundance of about 60.1%, while gallium-71 has an abundance of approximately 39.9%. These percentages can vary slightly in natural samples but are generally consistent.