Atomic Number and Mass Number

Zwitterion

________ and neutrons both weigh about one atomic mass unit or amount.

Atomic mass

________- The average mass of an atom, taking into account all its naturally occurring isotopes.

number of neutrons

Mass number- The sum of the number of protons and the ________ in an atom.

atoms of the same element

The number of neutrons can vary to produce isotopes, which are ________ that have different numbers of neutrons.

Atomic number

________- The number of protons in an atom.Atomic Number.

Neutral atoms of each element

________ contain an equal number of protons and electrons.