Post-transition metal packing structure. Tin forms Zintl phases such as NaSn, BaSn, KSn and CaSn. It has good corrosion resistance in air on account of forming a thin protective oxide layer. Pure tin has no structural uses. It is used in lead-free solders, and as a hardening agent in alloys of other metals, such as copper, lead, titanium and zinc. Lead is a soft metal (MH 1.5, but hardens close to melting) which, in many cases, is unable to support its own weight. It has a close-packed structure (BCN 12) but an abnormally large inter-atomic distance that has been attributed to partial
Hard and soft C or an alveolo-palatal , and occurs before not only , and , but also , , and . Another similar system with hard and soft is found in Faroese with the hard being and the soft being , and Turkish where the soft is . The Vietnamese alphabet does not have a hard or a soft per se. However, since it was inherited from European languages, the letter never occurs in "soft positions", i.e. before , and where is used instead, while never occurs elsewhere except in the digraph and a few loanwords. Hồ Chí Minh had proposed a simplified