Bombarding the atoms means that high energy particles are used to collide with the nucleus of the atoms. Particle accelerators are devises using various arrangements of electric and magnetic fields to speed up the movement of atomic particles. The purpose of an accelerator of charged particles is to direct a beam of a specific kind of particles of a chosen energy against a target.
Accelerators serve as valuable tools for scientific research into the nucleus of an atom.
They enable physicists to change the atom of one element into that of another element. This change, called transmutation, results from reaction that occur when accelerated particles collide with the nucleus of another atom. High energy accelerators also help physicists discover new kinds of particles and study their relation to the forces that hold the nucleus together. These new particles are created by smashing the nucleus with electrons or protons boosted to tremendous speeds. Accelerators are sometimes called atom smashers because of such experiments.