[huskywolf]

Hi can someone give me a simple explanation of what elementary particles are?
I know they cannot be divided into smaller particles , but are they electrons protons and neutrons?

Thanks

[Jorriss]

Electrons are. Protons and Neutrons are composed of Quarks, which are elementary particles.

[huskywolf]

Thanks so electrons are, but protons/ neutrons are not? but can be broken down into elementary particles .
So it would be incorrect to say an atom is composed of elementary particles/ as in protons and neutrons are 'not' elementary particles?

Thanks

[sjb]

Thanks so electrons are, but protons/ neutrons are not? but can be broken down into elementary particles .
So it would be incorrect to say an atom is composed of elementary particles/ as in protons and neutrons are 'not' elementary particles?

Thanks

Well, at our current level of understanding, quarks are indivisible, but then we probably thought the same of protons and neutrons 80 years ago, and of atoms 180 years ago.

Whether it's wrong to say an atom is composed of elementary particles may depend, for instance on whether you consider sandwiches to be made from bread, or wheat, or ... (probably a very bad analogy).

[huskywolf]

Ok thanks for the help people 

[Borek]

Well, at our current level of understanding, quarks are indivisible, but then we probably thought the same of protons and neutrons 80 years ago, and of atoms 180 years ago.

See http://arxiv.org/abs/1009.5069 - this is based on analysis of LHC experiments. Basically they have not found any traces of quarks substructure (or more precisely - they have pushed the energy level at which substructure can be not seen up to 3.4 TeV).

Not that I understand much from the abstract, I was explained the meaning somewhere else