What is antimatter?

Gnomon

Normal matter consists of negatively charged electrons in a cloud around a postive nucleus. Antimatter consists of a cloud of positive electrons (positrons) around a negatively charged nucleus. Antimatter can be constructed in particle accelerators, but it is shortlived, since it self-destructs when it collides with normal matter. Jan 30 04, 7:30 AM

Stew54

antimatter - matter consisting of particles with charges opposite that of ordinary matter. For example, in antimatter, protons have a negative charge while electrons have a positive charge. Jan 30 04, 7:32 AM

Senior Moments

Anti-matter can be described as the mirror of matter, containing anti-particles of the particles that constitute normal matter. Anti-particles are equal and opposite to matter particles in that they have an opposite charge and they rotate in an opposite direction. So whereas matter is composed of atoms, that are made up of the elementary particles (electrons, protons and neutrons), anti-matter is composed of anti-atoms that are made up of positively charges electrons known as positrons, negatively charged protons known as anti-protons, and anti-neutrons. Most theorists believe that at the time of the Big Bang anti-particles and particles were created in almost equal numbers. http://www.open2.net/nextbigthing/antimatter/antimatter_in_depth/in_depth.htm Jan 30 04, 7:33 AM