All noble gases have the maximum number of electrons possible in their outer shell (two for helium, eight for all others), making them highly stable.

所有的稀有气体元素的最外层电子数都是该层最大的可能数目：氦的最外层电子有两个，其它的稀有气体最外层电子数是八。这使稀有气体非常稳定。

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All noble gases have the maximum number of electrons possible in their outer shell (two for helium, eight for all others), making them highly stable.

所有的稀有气体元素的最外层电子数都是该层最大的可能数目：氦的最外层电子有两个，其它的稀有气体最外层电子数是八。这使稀有气体非常稳定。

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