Ar3d10

Ar3d10 is not the name of a compound or element; it is a shorthand notation used to describe a specific electron configuration: the argon core with a filled 3d subshell, written formally as [Ar]3d10. This configuration is encountered in discussions of transition metals in the fourth period, where the 3d subshell can be fully occupied while outer electrons occupy higher shells such as 4s or 4p.

In practice, Ar3d10 is often used as a focused representation of the inner-shell arrangement for elements like zinc in certain oxidation states. For example, the neutral zinc atom is [Ar]3d10 4s2, while the Zn2+ ion commonly adopts the configuration [Ar]3d10 after losing the two 4s electrons. The presence of a filled 3d subshell contributes to shielding of the outer electrons and influences the chemistry primarily through the behavior of the valence 4s electrons.

Because Ar3d10 is a shorthand nonstandard form, it is mainly found in computational chemistry, spectroscopy, and educational materials that emphasize inner-shell structure. It is not an official chemical symbol or a standalone species, and its use can vary depending on the context or software conventions. When encountered, it is helpful to recognize it as shorthand for a [Ar]3d10 core rather than a separate element or ion.

See also: electron configuration, argon, transition metals, zinc, d-block elements, ionization states.