So sodium-- let me draw its valence shell-- sodium's valence shell looks like this.

所以钠——让我画出它的价层——钠的价层看起来像这样。

The resulting vapor was variable, so it was difficult to meansure its valence.

蒸气是反复无常的。因些很难测量它的化合价。

However, researchers note that studying emotional valence, whether something is perceived as positive or negative, is different from studying what researchers call arousal, which tracks whether or not something activates the nervous system and helps us feel.

然而，研究人员注意到，研究情绪的效价，不管是感知到积极的还是消极的，都不同于研究人员所说的唤醒，它跟踪的是某样东西能否激活神经系统，并帮助我们感觉。