When Be is bombarded with `alpha`-particles, a grew element viz carbon is formed whereas, when gold is bombarded with `alpha`-particles, no new elements are formed. Explain.

Explanation

There are 79 protons in the nucleus of gold `(""_(79)Au)` atom, which `alpha`-particles are helium nuclei with 2 unit positive charges. The approaching `alpha`-particles are repelled strongly due to high positive charges of Au nuclei and thus suffers deflection. On the other hand, there are only 4 protons in the nucleus of beryllium `(""_(4)Be)` atom. hence, the coulombic force of repulsion between the Be nuclei and the `alpha`-particles are very weak compared to those between the gold nuclei and `alpha`-particles, due to low positive charge of Be nucleus. thus, the fast moving `alpha`-particle collide with Be nuclei and causes splitting: `""_(4)^(9)Be+""_(2)^(4)Be to ""_(6)^(12)C+""_(0)^(1)n`.