Why don't electrons fall into the centres of atoms?
because centrifugal and centripetal forces balances each other............ alexalok, Tue, 7th Jan 2014
Sadly, no. An accelerating charge radiates electromagnetic energy and would therefore spiral in to the nucleus. This is the fundamental problem with the Bohr model of the atom, and the reason why we have replaced the notion of orbiting electrons with "orbitals" - effectively, maps of the probability of finding an electron at any point in space. alancalverd, Tue, 7th Jan 2014
More exactly, an accelerating irregularity in the charge distribution radiates. A spinning electrically charged disk does not radiate. This is significant in re. electron motions in atoms, because the quantum states corresponding to definite energies have, for single atoms, circularly symmetric distribution patterns, and for molecules, the patterns are often asymmetric but still time-independent. Effectively there is a stationary probability distribution even though the electrons do have kinetic energy. Atomic-S, Wed, 8th Jan 2014
There is one rare instance where an electron does end up in the nucleus: a radioactive decay process called "electron capture".