化合价，原子价原子或原子团与其它原子反映时由所失、增加成共享的电子数目决定的化合能力 The combining capacity of an atom or a radical determined by the number of electrons that it will lose, add, or share when it reacts with other atoms.
五氧化物由五个氧原子和其它元素或基组成的化合物 A compound having five atoms of oxygen combined with another element or radical.
聚合物许多天然和人工合成的化合物中的任一种，通常具高分子的重量，包含最多可达上百万个的彼此重复且相连的单位，每一个单位都是一个相对较轻和较简单的分子 Any of numerous natural and synthetic compounds of usually high molecular weight consisting of up to millions of repeated linked units, each a relatively light and simple molecule.
氢与氧化合成水。 Hydrogen and oxygen combine/Hydrogen combines with oxygen to form water.
