所有的碱土金属元素的化合价都是+2，这使他们非常活泼，因为他们非常活泼，也不在自然界中直接出现。

All alkaline earth elements have an oxidation number of +2, making them very reactive. Because of their reactivity, the alkaline metals are not found free in nature.

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所有的碱土金属元素的化合价都是+2，这使他们非常活泼，因为他们非常活泼，也不在自然界中直接出现。

All alkaline earth elements have an oxidation number of +2, making them very reactive. Because of their reactivity, the alkaline metals are not found free in nature.

youdao