* Annihilation: When an electron and a positron collide, they annihilate each other. This means they are converted into pure energy in the form of gamma rays (photons).
* Mass-Energy Equivalence: Einstein's famous equation, E=mc², tells us that mass and energy are equivalent. The total energy before the collision (the combined rest mass of the electron and positron plus any kinetic energy) is equal to the total energy after the collision (the energy of the gamma rays).
* Conservation of Mass-Energy: While the electron and positron cease to exist as particles, their combined mass-energy is conserved. It's transformed into a different form of energy.
In essence, matter isn't "destroyed" in the annihilation process. It's simply converted into a different form of energy.
Important Note: While the law of conservation of matter is a fundamental principle, it's more accurate to speak of the law of conservation of mass-energy. This law encompasses the idea that the total amount of mass and energy in a closed system remains constant, even if it changes form.
