不传电的物体,叫做非导体,也叫绝缘体或电介质。盐类晶体、油、空气、玻璃、瓷、橡胶、琥珀等等都是非导体。非导体是由分子构成的,在这种分子中,有等量的正电荷和负电荷。有些非导体是由离子构成的,但这些离子不能自由地在非导体中移动。在电力的作用下,电介质中的电荷只能够稍微改变自己的位置或取向。原来在非导体中,成对结合着的异号电荷(有极分子)的取向是无规则的。虽然拿一个分子来看,它一端带正电,一端带负电(整个分子仍然是中性的);但就因为这些分子的电荷取向不规则,所以不论拿整个或是部分非 Non-transmission objects, called non-conductors, are also called insulators or dielectrics. Salt crystals, oil, air, glass, porcelain, rubber, amber, etc. are all non-conductors. Non-conductors are made up of molecules in which there is an equal amount of positive and negative charges. Some non-conductors are made of ions, but these ions cannot move freely in non-conductors. Under the influence of electricity, the charge in the dielectric can only slightly change its position or orientation. Originally in non-conductors, the orientation of the paired bounded charge (polar molecules) was irregular. Although viewed from a single molecule, it is positively charged at one end and negatively charged at one end (the entire molecule is still neutral); but because the charge orientation of these molecules is irregular, whether or not the whole or part is not