User:Siluna/Group 10 element

Group 10, numbered by current IUPAC style, is the group of chemical elements in the periodic table that consists of nickel (Ni), palladium (Pd), platinum (Pt), and darmstadtium (Ds). All are d-block transition metals. Palladium and platinum belong to the platinum group metals. All known isotopes of darmstadtium are radioactive with short half-lives, and are not known to occur in nature; only minute quantities have been synthesized in laboratories.

The ground state electronic configurations of palladium and platinum are exceptions to Madelung's rule []. All three of nickel, palladium, and platinum are commonly found in the +2 oxidation state, while platinum is also commonly observed in the +4 oxidation state.

Chemical properties
The ground state electronic configurations of palladium and platinum are exceptions to Madelung's rule. According to Madelung's rule, the electronic configuration of palladium and platinum are expected to be [Kr] 5s2 4d8 and [Xe] 4f14 6d2 5d8 respectively. However, the 5s orbital of palladium is empty, and the 6s orbital of platinum is only partially filled. In general, the ground state electronic configurations of heavier atoms and transition metals are more difficult to predict.

Group 10 elements are observed in oxidation states of +1 to +4. The +2 oxidation state is common for nickel and palladium, while +2 and +4 are common for platinum. Oxidation states of -2 and -1 have also been observed for nickel and platinum, and an oxidation state of +5 has been observed for palladium and platinum. Platinum has also been observed in oxidations states of -3 and +6. Theory suggests that platinum may produce a +10 oxidation state under specific conditions, but this remains to be shown empirically.

Physical properties
Darmstadtium has not been isolated in pure form, and its properties have not been conclusively observed; only nickel, palladium, and platinum have had their properties experimentally confirmed.

Nickel, platinum, and palladium are typically silvery-white transition metals, and can also be readily obtained in powdered form. They are hard, have a high luster, and are highly ductile. Group 10 elements are resistant to tarnish (oxidation) at STP, are refractory, and have high melting and boiling points.

Biological role and toxicity
Platinum complexes are commonly used in chemotherapy as anticancer drugs due to their antitumor activity. Palladium complexes also show marginal antitumor activity, yet its poor activity is labile compared to platnium complexes.