helium

• n. [化学] 氦（符号为He，2号元素）
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1. hel- / heli- "sun" + -ium.
2. 因为该元素最初是在日食期间从太阳光谱中探测出来的，因此就取了这个名字，-ium 本是用于金属元素的后缀，由于该元素最初被认为是一种碱金属，所以就使用了这个后缀。
helium 氦，氦气

helium (n.)
1868, coined from Greek helios "sun" (see sol), because the element was detected in the solar spectrum during the eclipse of Aug. 18, 1868, by English astronomer Sir Joseph N. Lockyer (1836-1920) and English chemist Sir Edward Frankland (1825-1899). It was not actually obtained until 1895; it was assumed before that to be an alkali metal, hence the ending in -ium.
1. Helium is a very light gas.

2. Helium is a gas used in balloons.

3. Unlike helium - 4, it cannot be produced by radioactive decay.

4. The helium - 3 apparently became trapped when the earth was formed.

5. After hydrogen, the atom with the simplest structure is that of helium.