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
Anniversary Trouble Anniversary Trouble Anniversary Trouble is a 1935 "Our Gang" short comedy film directed by Gus Meins. It was the 134th "Our Gang" short (46th talking episode) that was released. Spanky's appointment as treasurer of the Ancient and Honery Order of Woodchucks occurs on the same day as his parents' wedding anniversary. Spanky's father (Johnny Arthur) puts money in an envelope as an anniversary gift for his wife (Claudia Dell), then absent-mindedly uses the envelope as a bookmark. Spanky's mother sees Spanky hide the gang's club money in a cookie jar and jumps to the conclusion that Spanky stole her gift