isn't standard model says there is 99.99% empty space within atoms? how empty space stands any pressure?

No. The the current widely accepted model is that the nucleus takes up ~0.01% of the volume of the atom, and the electrons take up the remaining 99.99%. We explain over and over--the electrons behave as waves, and they are spread out through the entire space of the atom.

Even if you want to use a model in which the electrons are point particles whizzing about within the atom, they would still exert/withstand significant pressure. The air around us (or any gas at reasonable pressures) is about 90% "empty space" (the volume of the molecules is a really tiny fraction of the total volume of the gas--for instance a nitrogen molecule has a van der Waals volume of about 65 Å

^{3} or 6.5 x 10

^{–27} m

^{3}. One mole of nitrogen molecules would have a collective volume of 6.02 x 10

^{23} x 6.5 x 10

^{–27} or 3.9 x 10

^{–3} m

^{3}; but at standard atmospheric pressure and temperature, the gas fills a volume of 2.2 x 10

^{–2} m

^{3}--therefore, if we assume air is only nitrogen, it would be about 82% "empty".

The key here is that the molecules are whizzing around really quickly, so *on average* every point of space is filled with .18 molecules, even though at any given instant only 18% of points have a nitrogen molecule and 82% have none.

how many volts is in between proton and electron in a hydrogen atom? why there is no discharge? is the empty space such a good insulator?

Again, you are confusing macroscopic and microscopic phenomena. "Discharge" as commonly understood is flow of electrons or flow of charged ions. There couldn't possibly be discharge from an electron--it would have to be the electron itself moving. But! As we have already pointed out many, many, many times in this thread: the electron is already centered about the nucleus, and cannot "get any closer" because it naturally spreads out to take up the whole volume of the atom.

We understand that this is a very tricky and counter-intuitive subject, but the experimental and theoretical evidence is very clear--electrons in atoms and molecules are best described as waves, and once you accept that premise, everything else falls into place very nicely.