Period 6 element devices though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alcohol-filled, galinstan-filled, digital, or thermistor-based instruments. It remains in use in scientific research applications and in amalgam material for dental restoration. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave ultraviolet light which then causes the phosphor to fluoresce, making visible light. Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray other metal resembles tin but discolors when exposed to air. The
SN 2002cx similar to other type Ia supernovae before 5 days after max, although it is somewhat redder. After 5 days after max SN 2002cx gets progressively redder, although still slightly bluer than SN 1991bg. At 25 days after max SN 2002cx continues to redden, while SN 1991bg starts to get bluer. SN 2002cx's V – I color is red for all times, only slightly bluer than SN 1991bg before 25 days after max, and redder after 25 days after max. SN 2002cx SN 2002cx is a peculiar type Ia supernova. It was discovered in May 2002 by a team of researchers