Final answer:
Man-made (synthetic) elements are produced through the bombardment of an atom by neutrons or alpha particles. This process results in a nuclear transmutation reaction, creating new elements with atomic numbers significantly greater than that of the target nucleus.
Step-by-step explanation:
Bombardment of an atom by neutrons or alpha particles.
Man-made (synthetic) elements are produced through the bombardment of an atom by neutrons or alpha particles. These particles collide with the target atom's nucleus, causing a nuclear transmutation reaction. This process can result in the creation of new elements with atomic numbers significantly greater than that of the target nucleus.
For example, by bombarding a beryllium atom with alpha particles, German researchers were able to produce unknown particles that were electrically neutral and had strong penetrating power. Another method involves bombarding known elements with sub-atomic particles such as neutrons or alpha particles to synthesize larger elements.