Why electron doesn collide with proton even though they have opposite charge?
Pretty much for the same reason the Moon doesn’t collide with Earth even though it is attracted to the planet by gravity… kinetic energy. There is an E field around each atom emanating from the positive charged protons. In similar fashion there is a g field coming from Earth’s mass. The E field forms a potential energy gradient on the charge q of each electron like the g field does for mass m. When an electron is pulled towards the nucleus, it picks up kinetic energy; much in the same manner that the Moon does as it falls towards the planet. That is, the loss of potential energy is converted into kinetic energy for both the electron and the Moon. That increase in kinetic energy throws the electron back into its orbital just as the increase in KE puts the Moon back in place. And, that is why the electron doesn’t not typically collide with the nucleus. Kinetic energy. Note, due to quantum jitters, there is a slim possibility that an electron can be found within the nucleus of its atom.
