helium
helium 英 [ˈhi:liəm] 美 [ˈhiliəm]
n. [化学] 氦（符号为He，2号元素）
名词复数:heliums
- The element helium is a colorless, odorless gas. Because helium is lighter than air, it's commonly used for filling balloons to make them float.
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- n. [化学] 氦（符号为He，2号元素）
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1. helium is a gas used in balloons.
氦是一种用于气球的气体。
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2. We have a helium nucleus and one electron.
我们有一个氦核和一个电子。
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3. If helium loses on electron, what do we have?
如果氦原子失去了一个电子，我们得到了什么？
- helium (n.) 1868, coined from Greek helios "sun" (from PIE root *sawel- "the sun"), 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; before then it was assumed to be an alkali metal, hence the ending in -ium.
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