So there's this stuff called "antimatter." You may have heard of it. It's just like normal matter, with all the same properties and all the same abilities to make up atoms and molecules, except for one crucial difference: It has an opposite charge. Take the humble electron, for example. Mass of 9.11 x 10^-31 kg. Quantum spin of 1/2. Charge of 1.6 x 10^-9 coulombs.