Tin pest related problems such as tin whiskers. At 13.2 °C (about 56 °F) and below, pure tin transforms from the silvery, ductile metallic allotrope of β-form "white tin" to the brittle, nonmetallic, α-form "grey tin" with a diamond cubic structure. The transformation is slow to initiate due to a high activation energy but the presence of germanium (or crystal structures of similar form and size) or very low temperatures of roughly −30 °C aids the initiation. There is also a large volume increase of about 27% associated with the phase change to the nonmetallic low temperature allotrope. This frequently makes tin
Diplomatic gift A 2012 gift of a "British" table tennis table to President Obama seemed ideal until it was revealed that it was designed in Britain but made in China, evoking worries about the decline of British manufacturing industry. Diplomatic gifts take diverse forms: Diplomatic gift A diplomatic gift is a gift given by a diplomat, politician or leader when visiting a foreign country. Usually the gift is reciprocated by the host. The use of diplomatic gifts dates back to the ancient world and givers have competed to outdo each other in the lavishness of their gifts. Examples include silks given to