Which of these statements about electron energy levels in hydrogen atoms is true?
(a) An electron in the hydrogen atom is best represented as a traveling wave.
(b) An electron with positive total energy is a bound electron.
(c) An electron in a stable energy level radiates electromagnetic waves because the electron is accelerating as it moves around the nucleus.
(d) The orbital angular momentum of an electron in the ground state is zero.
(e) An electron in state n can make transitions only to the state n + 1 or n − 1.