All protons have a positive charge. The antimatter equivelant to
the proton, the antiproton, has a negative charge. Every element of
matter (hydrogen, helium, etc.) has an equivalent antimatter
element (antihydrogen, antihelium, etc.) and just as every element
of matter has a proton in its the nucleus (which, again, is
positively charged), every corresponding anti-element has an
anti-proton in its nucleus (which is negatively charged).
There are also theoretical "hybrid" elements (called exotic
elements of atoms) consisting of both matter an antimatter
components, such as a proton and antiproton orbitting each other
(this is called Protonium).
