Sub-atomic Particles

What are Elements

Elements are either made up of atoms of molecules. Atoms can be further divided into sub-atomic particles and depending on the number of particles, it determines where the element ends up on the periodic table. 

Today we shall focus on the sub-atomic particles which are made up of protons, neutrons and electrons. Protons and neutrons, or nucleons for short, can be found in the nucleus of an atom. There are also electrons circling the atoms in areas called shells or orbitals. 

Each proton carries one positive charge, while each electron carries a negative charge. Neutrons, well they don't carry any charge. Anyways, in each atom, there will be an equal number of protons and electrons so they cancel each other out and the atom will be electrically neutral. 

This explains why you don't get electric shocks everywhere you go. If an atom doesn't have an equal number of protons and electrons, you can call them ions. This means the atom is charged, and depending on whether you have more protons or electrons, your atom will either be negatively or positively charged. 

Ions can be dangerous when inhaled, because when negatively charged ions and positively charged ions come into contact, it leads them to stick to things, including your lungs and throat, which can lead to build-up over time and exacerbate conditions like asthma attacks, blisters in lungs, blocked passages from particles and even permanent lung damage. (Taken from eHow.com)

Particles in an atom are very light. One proton weighs approximately 1.67 x 10^-27, which is 0.000000000000000000000000000167kg. So to make things simpler, our wonderfully lazy scientists came up with the standard unit "amu" or "atomic mass unit". This is also known as "relative mass".

I do have one question though...

Why is it that electrons don't "fall" into the nucleus?

Apparently, I've been reading up and this has to do with the uncertainty principal. The electron cannot have a defined position in the nuclei of atoms means that it must occupy every other space within the atom in a wave of possibilities. If the electron was positioned with great certainty within the nuclei of atoms, their momenta becomes infinitely uncertaint. But instead, they seem to have energy-orbits inside of atoms which determine the chemical struture of the universe. Another interesting thing to note is that electrons could not be in the center of atoms, because if they where, matter would drastically sink in size. 

We already know of nature objects which undergo this process, and they go by the name of neutron stars. In classical mechanics, electrons couple so strongly with protons that they should collapse all the time; and would in classical physics mean that every nucleus of every atom would gobble up the electrons in about 100 microseconds.

[Taken from: http://www.thenakedscientists.com/forum/index.php?topic=26362.0]

I know the above explanation is kinda confusing so I decided to give an analogy. It's like coasting along on a skateboard at a constant speed, and you see something to your right that you are attracted to, maybe a cute puppy. You start to turn towards it, but your forward your motion will carry you past it. If the conditions are right, you'll keep turning, but your forward motion will keep making you miss them. You'll just circle them, always turning toward them, but never getting there. It's like that for the electrons and planets too. They can't slow down, so they just keep turning and overshooting, forever circling the object.