1) select the "chain reaction" tab at the top. experiment with changing the settings and shooting the neutron gun and watch what happens. then answer the questions below.2) click the ‘reset all’ button and then set the initial number of u-235 nuclei to 100 and u-238 to 0. what happens when you fire the neutron gun? 3) explain what makes this a "chain reaction".4) click ‘reset’ and then set the initial number of u-238 nuclei to 100 and u-235 to 0. explain what happens when you fire the gun. does this cause a chain reaction? try multiple times to start a chain reaction with the u-238. explain why this happens.