jatslo nice jobing using google and quoting stuff that you don't understand one bit. BTW just so you know people don't have to quote google to be right because lots of people here have taken classes and read numerous literature on Physics.<br /><br />You want to know what happens when an antiparticle and a particle meet? Here<br /><br /><br />You see the picture? First is the before situation, then the after Situation.<br /><br />What you have Before are 2 electrons at rest with a rest mass of 511,000eV, ei E = K + MC^2, where K = 0 and MC^2 = 511,000eV. <br /><br />So that the total energy of the systme is <br />E = MC^2(electron) + MC^2(positron)<br />Note Energy is a scalar and does not depend on Charge, Direction, or if its an antiparticle or not.<br /><br />So when the two come together, because they have opposite charges and opposites attract, by Conservation of energy the two photons that result must have a total energy of E that we found before.<br /><br /><br />Also we know that the energy of a photon is h(nu), where (nu) is the frequency and, (nu); = c/(lamda)<br /><br />where (lamda) is the wavelength of the photon and c is the speed of light we can say <br /><br />h(nu) = hc/(lamda)<br /><br />h being plancks constant and c being the speed of light multiply into a nice number for us to use being 1240eV*nm<br /><br />So <br />Einitial = Efinal<br />Einitial = MC^2(electron) + MC^2(positron)<br />Einitial = 511,000eV + 511,000eV<br />Einitial = 1,220,000eV<br />1,220,000eV = hc/(lamda) + hc/(lamda)<br />1,220,000eV = 2(1240eV*nm/(lamda))<br />(lamda)= 2480eV*nm/1,220,000eV<br /><br />which gives us<br />(lamda) = 0.00203nm<br />or<br />(lamda) = 2.03x10^-12m<br /><br />So the photons that result from the annihilation of the electron and the positron each have a wavelentgh of 2.03x10^-12m<br /><br />going back to <br />(nu) = c/(lamda)<br />we can get the frequency<br />(nu) = (3.0x10^8m/s)/(2.03x10^-12m)<br />(nu) = (1.477x10^20)/s<br />or<br />(nu) = .1477 quintillion Hz<br /><br />ie, you get a VER