Which of the following transitions within an atom is not possible?
A) An electron begins in an excited state and then gains enough energy to jump to the ground state.
B) An electron begins in the ground state and then gains enough energy to jump to an excited state.
C) An electron begins in the ground state and then gains enough energy to become ionized.
D) An electron begins in an excited state and then gains enough energy to become ionized.
Answer: A