Lithium atoms split when they are blank with a stream of protons

The answer is; bombarded

John Cockcroft and Ernest Walton split the lithium atom using accelerated protons. The atomic nuclei were split and the physicist observed alpha particles (two protons and two neutrons bound together into a particle identical to a helium-4 nucleus) as one of the products. The experiment also led to the discovery of the neutron and positron subatomic particles.