Question

what term is used to describe \a measure of the size of an atom\ (17/35) with options: energy levels, atomic radius, orbit, chemical reactivity

Explanation:

To solve this, we analyze each option:

• "Energy levels" refer to the regions around the nucleus where electrons are likely to be found, not a measure of atomic size.
• "Atomic radius" is defined as a measure of the size of an atom, as it quantifies the distance from the nucleus to the outermost electron shell (or the effective range of the electron cloud).
• "Orbit" (in the context of older atomic models) or "orbital" (in modern quantum mechanics) describes the path or region of electron probability, not size.
• "Chemical reactivity" relates to how readily an atom undergoes chemical reactions, not its size.

Answer:

B. atomic radius (assuming the options are labeled A: energy levels, B: atomic radius, C: orbit, D: chemical reactivity as per the order in the image)