ambient conditions; a protective film of oxide prevents further corrosion. Indium is a soft, highly ductile metal (MH 1.0) with a low tensile strength. It has a partially distorted crystalline structure (BCN 4+8) associated with incompletely ionised atoms. The tendency of indium '...to form covalent compounds is one of the more important properties influencing its electrochemical behavior'. The oxides of indium in its preferred oxidation state of +3, namely In2O3 and In(OH)3 are weakly amphoteric; it forms anionic indates in strongly basic solutions. Indium forms Zintl phases such as LiIn, Na2In and Rb2In3. Indium does not oxidize in air at ambient conditions. Thallium is a soft, reactive metal (MH 1.0), so much so that it has no structural uses. It has a close-packed crystalline structure (BCN 6+6) but an abnormally large interatomic distance that has been attributed to partial ionisation of the thallium atoms. Although compounds in the +1 (mostly ionic) oxidation state are the more numerous, thallium has an appreciable chemistry in the +3 (largely covalent) oxidation state, as seen in its chalcogenides and trihalides. It is the only one of the Group 13 elements to react with air at room temperature, slowly forming the amphoteric oxide Tl2O3. It forms anionic thallates such as Tl3TlO3, Na3Tl(OH)6, NaTlO2, and KTlO2, and is present as the Tl− thallide anion in the compound CsTl. Thallium forms Zintl phases, such as Na2Tl, Na2K21Tl19, CsTl and Sr5Tl3H. Nihonium is expected to have a hexagonal close-packed crystalline structure, albeit based on extrapolation from those of the lighter group 13 elements: its density is expected to be around 16 g/cm3. A standard electrode potential of +0.6 V is predicted for the Nh+/Nh couple. The relativistic stabilisation of the 7s electrons is very high and hence nihonium should predominantly form the +1 oxidation state; nevertheless, as for copernicium, the +3 oxidation state should be reachable. Because of the shell closure at flerovium caused by spin-orbit coupling, nihonium is also one 7p electron short of a closed shell and would hence form a −1 oxidation state; in both the +1 and −1 oxidation states, nihonium should show more similarities to astatine than thallium. The Nh+ ion is expected to also have some similarities to the Ag+ ion, particularly in its propensity for complexation. Nihonium oxide (Nh2O) is expected to be amphoteric. Group 14 Germanium is a hard (MH 6), very brittle semi-metallic element. It was originally thought to