But now, because it has an extra electron, it has two electrons in the outermost two s orbital. So the ratio in lithium of inner electrons to outer electrons is two to one, while the ratio of inner to outer electrons in Beryllium is two to two. So the ratio is greater in this guy. The significance of this is the following. Because our ratio of inner to outer is greater, that means the inner electrons will take away or shield more charge. So lithium will experience a strong shielding effect due to these inner electrons.