Carbon-12 and carbon-13 are isotopes of carbon.

Isotopes of an element share the same number of protons but have different numbers of neutrons. Let's use carbon as an example. There are three isotopes of carbon found in nature – carbon-12, carbon-13, and carbon-14. All three have six protons, but their neutron numbers - 6, 7, and 8, respectively - all differ.

Explanation:

Of course they are, why wouldn't they? Carbon 12 is the isotope found the most in earth's surface. Carbon 13 takes up about 1.1 percent of the earth's surface.

Explanation:

precipitation

explanation:

when it goes from cloud to rain/back to earth in the form of rain