226 88 Ra = = 222 86 Rn+42 He. The kinetic energy is calculated according to the conservation of kinetic energy: after fission, mv=mv, so the velocity ratio of particle A and radon core is opposite, which is11:2. The kinetic energy is 0.5mv square, that is, 0.5 * 4 *1*11:0.5 * 222 * 2 * 2 kinetic energy ratio 165438+. Radius R=mv/qb. Mv is the same, B is the same, and the radius ratio is inversely proportional to the number of protons, which is 1: 43.