2. An important reaction for generating fusion energy in reactors is 2H + 3H --> He +n (a) Calculate how much energy is released during the stacking. (b) How many atoms of Deuterium (2H) are needed to cover Sweden's energy needs of 160 TWh for this reaction, and how much mass does it correspond to? A radioactive preparation contains 120 g of the nuclide 239U. (c) Write the decay reaction for 239U. (d) How much mass of remains after 4.5 hours?6. A particle has a speed of 96% of the speed of light and a mass of lu. The particle is unstable and its lifetime is 150 ns. It passes through a room where we stand and observe. (a) How long do we think the lifetime of the particle is? (b) The room is 10 m long, but how far does the particle feel as it passes? (c) How much of the particle's total energy is rest mass