Now, remember, the formation of the ionic bonds was from group one and group two, and over here with group six and seven.

现在请记住，离子键的形成,从第一族和第二族元素，与六七主族的元素相互构成的。

麻省理工公开课 - 固态化学导论课程节选

Here is an example that shows some very, very metallic elements, groups one and two, and some non-metallic elements over here, five, six and seven.

举个例子,这个例子表明金属元素，第一族和第二族，与一些非金属元素,在这里，第五族，第六族，和第七族。

麻省理工公开课 - 固态化学导论课程节选

So if we consider lithium, potassium, and sodium, they're all together in the same group on the periodic table, knowing what we do about biology we can immediately think of sodium and potassium, or even just knowing what you know about table salt, for example, that these are two elements that we find, and particularly in the ion form in very high concentrations in our body.

我们来考虑一下锂，钾和钠，它们都在周期表中的同一族里，想要知道我们将元素周期律,用到生物学会怎么样，我们首先想到的就是钠和钾，甚至只需要知道食盐，我们发现它们是以很高浓度的离子形式,存在于我们体内的两种元素。

麻省理工公开课 - 化学原理课程节选