he.li.um
n.Symbol He (名词)符号 He A colorless, odorless inert gaseous element occurring in natural gas and with radioactive ores. It is used as a component of artificial atmospheres and laser media, as a refrigerant, as a lifting gas for balloons, and as a superfluid in cryogenic research. Atomic number 2; atomic weight 4.002'; boiling point -2'8.9=C; density at 0=C 0.785 gram per liter.See table at element 氦:自然界天然气体或放射性矿石中一种无色、无味的惰性气体状成分。用作人造大气层和镭射媒体的组成部分,和用作制冷剂及飞行气球的气体,还在低温学研究中用作超流体。原子序数2;原子量4.002';沸点-2'8.9=C;浓度在0=C时为每升0.785克参见 element
来源:From Greek hôlios [sun (so called because its existence was deduced from the solar spectrum)] * see s3wel- 源自 希腊语 hôlios [太阳(该元素的存在首先是在太阳光谱中测得,故名)] *参见 s3wel-