That's what stars do all the time. For example, in the sun (and MOST other stars), deep down in the center of the sun's core, two atoms of Hydrogen get squashed together so hard that they blend into one atom of Helium AND release some energy. That's where the sun's energy all comes from. It's called "nuclear fusion". It needs tremendous temperature and pressure to happen. We know how to do it, but we can't control it. So far, the only thing we've ever been able to use it for is Hydrogen bombs.
There are 92 elements on the Periodic Table that are found in nature, plus another 20 or so that have been made in the laboratory, but only a few atoms of them.
While the body is falling, it will not experience terminal velocity. As each time it keeps falling its speed will increase due to the acceleration of gravity g = 9.81[m / s^2]. Its final speed will be reached at the moment when the body touches or impacts the ground.
