Moving around the nucleus are extremely tiny particles, called electrons, which revolve around the nucleus in much the same way as the nine planets do around the sun.

• 参考译文：围绕着原子核运动的是一些极其微小的粒子，称为电子，这些电子围绕着原子核旋转，正像九大行星围绕着太阳旋转一样。