Final answer:
Most of the volume of an atom is empty space, more than 99 percent. The tiny nucleus at the center of the atom, made up of protons and neutrons, holds nearly all the atom's mass, while electrons occupy the vast space around the nucleus and prevent solid objects from passing through each other.
Step-by-step explanation:
The question 'What is most of the volume of an atom?' pertains to the structure of an atom within the field of Chemistry. In an atom, the majority of the volume—more than 99 percent—is actually empty space. This might seem counterintuitive since solid objects feel solid and impenetrable to us. The reason for this is that atoms consist of a centrally located nucleus, which is composed of protons and neutrons, and this nucleus contains nearly all the atom's mass. The protons carry a positive electric charge, while the neutrons are uncharged. Surrounding this tiny nucleus is a much larger volume of space that contains the electrons, which are negatively charged particles with such a minuscule mass that they are far less than that of protons or neutrons.
Electrons reside in the space around the nucleus and their exact location cannot be pinpointed due to their quantum nature; instead, their presence is described by a probability distribution commonly referred to as an 'electron cloud.' Because of the repulsion between these negatively charged electrons, solid objects do not pass through each other despite the vast empty space within the atoms. Even though the volume of a nucleus is proportional to the number of nucleons—protons and neutrons—it contains, the nucleus itself is incredibly small compared to the atom's total volume.