A neutral subatomic particle found in the nucleus of the atom.

The sum of the protons and neutrons in the nucleus.

A visual model of the most likely locations for electrons in an atom

Dense, positively charged mass located in the center of an atom.

The arrangement of electrons in the orbital of an atom

A positively charged subatomic particle found in the nucleus of the atom.

A region of space around the nucleus where an electron is likely to be found.

When all electrons in an atom have the lowest possible energies

The possible energies that electrons in an atom can have.

Atoms of the same element that have different numbers of neutrons and different mass numbers.

A negatively charged subatomic particle that is found in the space outside the nucleus