Complex sentence: The thermodynamically stable structures of metallic elements adopted at standard temperature and pressure (STP) are color coded and shown below, the only exception is mercury, Hg, which is a liquid and the structure refers to the low temperature form.
Split into simpler sentences: The thermodynamically stable structures of metallic elements adopted at standard temperature and pressure (STP) are color coded and shown below. The only exception is mercury, Hg, which is a liquid and the structure refers to the low temperature form.