A proton has positive charge and an electron (has) a negative charge, but a neutron has neither.
质子带有一个正电荷，电子带有一个负电荷，但这两种电荷中子都没有。
2
Between these two tiny particles, the proton and the electron, there is a powerful attraction that is always present between negative and positive electric charges.
在质子和电子这两个微粒之间有一个很大的吸引力，而这个吸引力总是存在于正、负电荷之间。
3
Unlike either the electron which has a negative charge or the proton which has a positive charge, the neutron has no charge at all.