Final answer:
The property that distinguishes antimatter from matter is charge; particles and antiparticles have the same mass and spin but opposite charges, and upon meeting, they annihilate and convert into energy.
Step-by-step explanation:
The property that commonly distinguishes antimatter from its matter analogue is charge. While particles and antiparticles share the same mass, spin, and often other properties, the charge is the primary characteristic that is different.
For instance, a positron is the antiparticle of an electron, and it has the same mass and spin as an electron, but it carries a positive charge instead of a negative one. When matter and antimatter meet, such as an electron and a positron, they annihilate each other, and their mass is converted into energy according to the mass-energy equivalence equation E = mc².