Define genus and species. how are they related to the binomial nomenclature of an organism?

A genus is typically the name for a small group of closely related organisms. The second part of a scientific name, axyridis in this example, is the specific epithet. It is used to identify a particular species as separate from others belonging to the same genus.

i'd say that the moon rock is about 2.2 billion years old.

the answer is:

carbon dioxide