A neutral atom of argon has eight valence electrons.
Argon is a noble gas located in group 18 of the periodic table. The atoms in this group are known for their stable electron configurations, which are achieved when they have a full outer shell of electrons. For argon, the electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶. The outermost shell (the third shell) contains 8 electrons: 2 in the 3s subshell and 6 in the 3p subshell. Since argon is neutral, its number of valence electrons, responsible for chemical bonding, remains at eight, indicating that it is chemically inert and does not readily react with other elements.