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
Wedding reception of a couple's entire wedding budget is spent on the reception alone. This is primarily due to the cost of food and alcohol. Wedding traditions vary between countries, and between regions of the same country. Some traditions include: Unless the wedding couple has a wedding registry, it is best not to give gifts or gift certificates. For Chinese weddings, cash or a cheque is always the best gift. In addition to that, some elder relatives might also give gold jewelry. The cash or cheque should be in a red envelope or red pocket with the givers' names on it, and