1. For example, the atomic number of Carbon is 6; this means that there are six positively charged protons in the nucleus, and six negatively charged electrons whirling around.
例如，碳的原子数是6，这就是说，原子核中有6个带正电荷的质子和6个围绕其旋转的带负电荷的电子。信号词for example后面的内容是对前者的举例说明。
atomic number 6
2. Carbon ≈ C, carbon, carbon copy, carbon paper, atomic number 6
n。碳，复写纸
3. So similarly, as we now move up only one more atom in the table, 3 so to an atomic number of three or lithium, now we're going from six variables all the way to nine variables.
类似地就像我们现在，移动到周期表中仅仅多一个电子的情况，移动到一个原子数为，或者锂元素，现在我们从6个变量到了9个变量。