不过由于人类在非洲这种炎热的气候中进化，汗水带走了身体中的钠。

But as man evolved in the hot climate of Africa, perspiration robbed the body of sodium.

其使用一种特殊的过滤膜充当分子过滤器，凭借让水份子通过而留下那些使水变咸的离子，诸如钠和氯化物离子。

This uses special membranes which act as molecular sieves by passing water molecules while holding back the ions, such as sodium and chloride, that make water salty.

但盐和几十种含有钠的化合物——盐里的一种元素，与高血压有关——在食品杂货店里从这一头到另一头的加工食品里无所不在。

But salt and dozens of compounds containing sodium - the element in salt linked to hypertension - have become omnipresent in processed foods from one end of the grocery store to the other.

This cation is attracting the chloride next to it and it is repelling the sodium as the next nearest neighbor.

这一阳离子被邻近的氯离子所吸引,并排斥钠离子,因为这是其最邻近的离子。

It is 1.7475. Conclusion: if I start to react sodium with chlorine, the result is a crystal, a three-dimensional array.

这是1。7475，结论就是：,如果我使钠和氯反应，结果将会是一个晶体，一个三维排列。

if we're actually thinking about electron configuration and we look at lithium, sodium and potassium, these all have one valence electron.

让我们来想一想,锂，钠，钾的电子排布，它们都只有一个价电子。