It's 109 . 5 is what we would expect for methane because it's tetravalent, but here we're just seeing something that's divalent, and they're both in p orbitals that are perpendicular to each other.

因为甲烷是四价的，我们预测是109。,但这里我们，看到的是二价的，它们都在。

麻省理工公开课 - 化学原理课程节选

The first one will be above and below the bond axis is where we'll see the electron density, and the second will be perpendicular to that, so it will be a density in front of and behind the bond axis.

第一个是在键轴之上和之下,我们可以看到电子密度，另外一个垂直于它，所以在键轴之前和之后有电子密度。

麻省理工公开课 - 化学原理课程节选

So what she's going to do is start loading up the electrons, and you see this wand here move slowly, and it takes a while to do it, start become perpendicular.

所以她将要加载电子，你们看到这个棒慢慢地移动，这个需要一段时间，开始变得垂直了。

麻省理工公开课 - 化学原理课程节选