Question

1. subatomic particles can usually pass unreflected through an atom because the volume of an atom is mostly -- filled with protons. filled with neutrons. empty space. filled by an uncharged nucleus.

Explanation:

Subatomic particles pass through atoms mostly undeflected because an atom's volume is predominantly empty space. The nucleus (containing protons and neutrons) is very small, and electrons occupy a tiny fraction of the atom's volume, leaving most of it as empty space. Options about being filled with protons/neutrons or an uncharged nucleus are incorrect (nucleus is charged, and protons/neutrons are in the nucleus, not filling the atom's volume).

Answer:

C. empty space (assuming the option with "empty space" is labeled C; if the original labels differ, adjust to the correct identifier with the text "empty space")