In 4000 million years [approx] the Sun will expand into a red star. All the inner planets, [Mercury, Venus, Earth, Mars], will be engulfed into its bigger diameter. We are about half way through the Sun's life-cycle, so no worries yet.
Anyway, back to the subject. I think that the analagy of the 'orbiting' electron round a nucleus being similar to Earth orbiting the Sun a bit strained. In conductors, the outer shell electrons, the so-called 'cloud' must be pretty loosely 'connected' to the molecules. It's more likely that they do a partial orbit and then traverse to another molecule, do a partial orbit, and so on. The fact someone mentioned that solids are all 'holes' means they could travel quite a ways before their next 'encounter'. Not in straight lines of course, since they are repelled by the other electons in the vicinity. Should this not mean that 'electrical resistance' should not be [i]quite[i/] a straight line on a graph, when plotted against voltage?
And of couse not only conductors have 'loose' electrons- you can mechanically rub some off a piece of amber, [or some plastics], which are non-conductive. If an amber molecule has 'free' electrons on its outer shell, why doesn't it conduct electicity well?
So many questions, so little time, Lord.
Alan
[This message has been edited by Alan Belson (edited 01-27-2006).]
