Which best describes what is made of matter

Atoms, and everything is made of matter.

All matter hass mass and volume. Mass is a general property of matter that is the amount of matter it an object. In other words, it is the amount of "stuff" there is. It is easy to confuse the terms "mass" with "weight" but they are fundamentally different properties. Volume describes how much space matter occupies. It is not how much "stuff" there is, though that definition is a common mistake that students make. The amount of space that an object takes up is the object’s volume.