Speelgoedmannetje spoke:
Is this thread about fusion of two atoms?
one with a core build up with electrons and neutrons and with orbiting protons and one with a core build up with protons and neutrons and with orbiting electrons? (Or was that anti-matter?)
;-) You're forgetting that protons have the same mass as neutrons, while electrons have so little mass as to be almost negligible. Switching their places wouldn't produce anything stable, I think.
Rather, anti-matter uses anti-matter particles. Positrons have the same scant mass as electrons, while anti-protons have equal mass to protons, but with the opposite charge.