英語 English：Oxygen
日語 Japanese：酸素 (さんそ)
定義 Definition：Oxygen is an element with atomic number 8. At standard temperature and pressure, oxygen appears as an oxygen molecule ($O_2$) in our daily life. We breathe air to get oxygen in our bodies.
類義 Synonym：Source of rust and fire
元素記号 Element symbol：O
語源 Origin：Greek Oxy (Of acid) + Greek Gen (Put forth) ⇒ English Oxygen
体系 System：化学 (Chemistry) ＞ 物質 (Substance) ＞ 分子 (Molecule) ＞ 原子 (Atom) ＞ 原子番号 (Atomic number) ＞ 水素 (Hydrogen) ＞ 酸素 (Oxygen)