电子层

例句：

1. 1. The atomic structure of an element is made up of electron layers.
   元素的原子结构由电子层组成。
2. 2.The innermost electron layer of the atom is called the nucleus.
   原子最内层的电子层称为核。
3. 3.The outermost electron layer in a metal is responsible for its electrical conductivity.
   金属的最外层电子层负责其导电性。