Question

What is a stable isotope for carbon?

Answer 1

Carbon-12 and Carbon-13

Explanation:

Carbon-12 has 6 protons and 6 neutrons in its nucleus. It is the most abundant isotope of carbon on earth.

Carbon-13 has 6 protons and 7 neutrons in its nucleus. It is also stable as it does not decay into other elements, but it is less abundant than Carbon-12

https://en.wikipedia.org/wiki/Isotopes_of_carbon