Sohel- That's a question that many people wonder about as they start to learn quantum mechanics.
Although the word "particle" is often used to describe electrons, protons, etc. the classical picture it evokes has almost nothing to do with how these objects actually behave. Small objects are never
located at a single point. It would require infinite energy for that to happen. They are always
spread out. They can even be found spread out into clouds with two or more lumps, in which case they are said to be "in two places at the same time".
You might think that all this is just a fuzzy description of an underlying reality in which the particles were really dots at particular places. However, the many violations found of the Bell Inequalities, described elsewhere on this site, show that no such picture can ever work.
(published on 08/30/2011)