Question

which is a characteristic of atoms? they come in ten major types. they are the smallest units of matter. they can be found in nonliving things only. they cannot combine together.

Explanation:

Atoms are the smallest units of matter. There are many more than ten major types of atoms (the elements on the periodic table). Atoms are found in both living and non - living things, and they can combine to form molecules and compounds.

Answer:

They are the smallest units of matter.