Question

1. the nucleus contains protons and neutrons.
2. electrons move around the nucleus in ______ levels (or shells).
3. an element is a pure substance made up of only one kind of

Explanation:

Electrons move around the nucleus in energy levels (or shells). This is a fundamental concept in atomic structure. Energy levels represent different regions where electrons are likely to be found, and they have specific energy values associated with them.

Answer:

energy