Annihilation occurs between an electron and positron at rest, producing three photons. Calculate the energy of the third photon of the energies if the two of the photons are 0.20 MeV and 0.30 MeV. Identify how many positrons can a 200 MeV photon produce?​

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.