When an atom emits an alpha particle, it may become a different element.
An alpha particle is a helium nucleus consisting of two protons and two neutrons. When an atom emits an alpha particle, it loses these two protons and two neutrons and therefore changes its atomic number and becomes a different element. The new element will have an atomic number that is two less than the original element.
For example, if an atom of uranium-238 emits an alpha particle, it will become an atom of thorium-234.
So, the correct statement is that an atom that emits an alpha particle may become a different element.