點解conductor有free electron但insulator冇?

Question

點解conductor有free electron但insulator冇?

但係非金屬ge東西外層電子都不是填滿的呀,那為何又沒有free electron??

Answer 1

Conductors are mostly metals, the most outer electron shells of their atoms are not fully filled. Generally, there is only one or two eelctrons in these outer shells. These electrons are thus only loosely held by the electrostatic forces of the nuceus and would escape from the atom to become free electrons.