An electron
Particles (small size i.e. size of about 10-10m or less) which form an element or compound i.e. "Atoms" or "Molecules" are reffered to as "Elementary Particles". Basically the term is referred to...
It is a basic particle in nucleus of an atom, the charge is +1, the exact opposite of an electron. Its mass is 1 a.m.u. about the same as a neutron.
quarks
Spin is either up or down and in positive half integer multiples of an angular momentum quantum constant: h/(2∏), where h is Planck's constant.