بریلیم

Beryllium is a chemical element with the symbol Be and atomic number 4. Its standard chemical formula is Be. The element has an atomic mass of 9.0121831 and an electronegativity of 2. Its electron configuration is listed as 1s² 2s² or [He] 2s². The ionic radius is 0.45.

Beryllium has a density of 1.850 and electrical conductivity of 25000000. It melts at 2349 and boils at 4532. The vapor pressure is 0. The primary oxidation state is 2. It was discovered in 1798. The Unicode character for the element is 鈹.

Safety guidelines include a time-weighted average exposure limit of 0.002 and a ceiling exposure limit of 0.0005. The level immediately dangerous to life or health is 4. The NIOSH Pocket Guide ID is 0054. In chemical databases, it is identified by PubChem CID 5460467 and InChIKey ATBAMAFKBVZNFJ-UHFFFAOYSA-N.