Question

1. choose the best answer.

an element that has a different number of neutrons than protons is a(n) ____.
isotope
ion
valence element
positron

Explanation:

• Isotope: Atoms of the same element (same number of protons) but different numbers of neutrons.
• Ion: An atom or molecule with a net electric charge due to loss or gain of electrons.
• Valence element: Not a standard term in this context. Valence refers to the combining capacity of an atom (related to electrons in the outermost shell).
• Positron: A positively charged sub - atomic particle (antiparticle of the electron).

Answer:

Isotope