In d-block elements, the valence subshell refers to the outermost subshell that contains electrons participating in chemical bonding. For d-block elements, the valence subshell is typically the outermost occupied d subshell.
In the periodic table, the d-block elements are located in the middle section, specifically from group 3 to group 12. The d subshell consists of five d orbitals, labeled as dxy, dxz, dyz, dx^2-y^2, and dz^2.
For d-block elements, the valence electrons are typically found in the outermost occupied d subshell. This means that the d subshell, rather than the s subshell, is considered the valence subshell for these elements.
It's worth noting that the specific electron configuration and the number of valence electrons in the d subshell vary depending on the element. However, in general, the outermost d subshell is the one involved in chemical bonding and determines the element's chemical properties.