• The number of protons in an atom is called the atomic number. The atomic number of xenon is 54, which means that a neutral xenon atom has 54 protons in its nucleus.

• The number of neutrons in an atom can vary. Atoms of the same element with different numbers of neutrons are called isotopes. Xenon has several naturally occurring isotopes, with the most common one having 74 neutrons.

• The number of electrons in a neutral atom is equal to the number of protons. Therefore, a neutral xenon atom has 54 electrons.