One gets a contribution from an electron outside closed shells and also a possible contribution coming from an incomplete shell or a hole in a closed shell.

化学键的形成来源于一个满壳层之外的电子，也有可能是形成于一个不完全的壳层或满壳层上的一个电子空穴。

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One gets a contribution from an electron outside closed shells and also a possible contribution coming from an incomplete shell or a hole in a closed shell.

化学键的形成来源于一个满壳层之外的电子，也有可能是形成于一个不完全的壳层或满壳层上的一个电子空穴。

youdao