snackster17 said:
I have little knowledge of particle physics in general and have been taught that atoms have positive and negative charges because of electrons. But how can an electron have a negative charge only? Are there spectrum's of the electromagnetic field which have different charges?
It has nothing to do with portions of the spectrum. Electromagnetic radiation (photons) is neutral, regardless of wavelength. Normal matter is composed of electrons, protons, and neutrons, these all have antimatter counterparts...so to answer your question, electrons are always negative because positive ones are called positrons. Protons and neutrons don't get special names, they have to settle for having anti- stuck in front of their names. (And anti-neutrons are still neutral, though neutrons do have other characteristics that are reversed in anti-neutrons, and the two will still annihilate with each other if brought together.)
The reason for the "normal" particles being so much more common than their antimatter counterparts is not completely understood. It's an unusual asymmetry of the universe that's still an area of research.
snackster17 said:
ok thank you for the replies. But how about when two electrons interact does that not create a photon?
While not exactly wrong, that statement's not particularly meaningful. Classically speaking, electromagnetic radiation is emitted by accelerating charges. Electrons can certainly radiate due to their interactions.
I also wonder if you're confusing protons and photons. The two are completely different particles.
snackster17 said:
so these virtual particles are energy carriers? why arent they on the standard model?
They are
force carriers. It's important to be precise about things like this...force is a different kind of quantity than energy.
As for them being in the standard model...why do you think they aren't? Photons for one are certainly part of the standard model...one of only four gauge bosons. What's special about virtual particles is that they are "off shell", not having the usual relationships between mass, energy, momentum, and velocity, which limits them to a temporary sort of half-existence.