So as we go across the row, and this is my beautiful picture of a periodic table here.

那么当我们沿着行向右走的时候，这是我漂亮的元素周期表。

麻省理工公开课 - 化学原理课程节选

And we know as we go across a row in the periodic table, what's happening is that z effective or the effective pull on the nucleus is increasing.

而我们知道沿着周期表的某一行向右看，有效核电量,或者说原子核的有效引力是在逐渐增大的。

麻省理工公开课 - 化学原理课程节选

Similarly we see as we go down the table, so as we're going from one row to the next row, so, for example, between helium and lithium, we see a drop; the same with neon to sodium, we see a drop here.

同样地，我们来看看沿着周期表往下走，当我们从一行到下一行时，比如，从氦到锂，我们看到了一个下落;,从氖到钠也一样，我们看到这里有个下落。

麻省理工公开课 - 化学原理课程节选

The only thing that's different is that they're one down on the periodic table, potassium is down one row, so it's going to be a little bigger, but when we're thinking about size, it maybe does not seem that significant to talk about the size.

它们唯一的不同点,就在于其中一个在周期表的下面，钾在下一行，因此它要稍微大一些，但是当我们考虑尺寸的时候，似乎讨论尺寸的意义不大。

麻省理工公开课 - 化学原理课程节选

And that's all that's big enough to pass through or small enough to pass through. And if we go up even just one row on the periodic table to potassium, what we actually see is now that it's going to be too large, and, in fact, a potassium solvated with one water molecule won't go through our channel.

就是这样刚好大到它通过,或者说刚好小到它通过,即使我们再沿着周期表往下走仅仅一行到钾离子，我们看到的就将是它的个头太大了，实际上，溶解于一个水分子的单个钾离子,不能穿过我们的通道。

麻省理工公开课 - 化学原理课程节选