Antimatter: ISOLATED!

[Welsh cake]

No, I am afraid you appeared to have said the samething i did, but much more confusedly. Whether it is a hydrogen atom or antihydrogen atom, it is neutral. The charge of the electron and the charge of the proton cancels each other in the case of hydrogen, and the charge of antiproton and the charge of positron cancels in the case of anti hydrogen. In both cases the atom is neutral while it's nucleus is not. Neutron plays no part.

In fact this applies to all atoms, not just simple hydrogen. All atoms are neutral until ionized, when loss of electrons or positrons allows the charge of the nucleus to be manifest.

Beg your pardon, I didn't realise you were talking about the antihydrogen atoms themselves and not the actual particles, yes you are quite correct, anti-atoms are electrically neutral.

Thus antihydrogen atoms do not repulse each other due to the like charge of their nuclei, nor can they react to magnetic containment through the overall charge of the atom. Instead they react because the different spacial distribution of the charges in their nuclei and the charge in their electron, or positron clouds.

We don't yet know. It hasn't been empirically proven or disproven if antimatter has negative gravitational mass or not, which is unlikely, but we haven't created enough anti-atoms to understand the interactions of antimatter or devised a technological mean to suspend them in a perfect vacuum so they don't drift out of the trap and therefore survive long enough to test this.