* Radiate electromagnetic energy when accelerated. This is a fundamental consequence of Maxwell's equations, which describe the behavior of electric and magnetic fields. Accelerating charges produce changing electric and magnetic fields, which propagate outward as electromagnetic waves.

* Spiral into the nucleus of an atom due to radiation. Because electrons are constantly accelerating in their orbit around the nucleus (due to their circular motion), they should be continuously radiating energy. This energy loss would cause the electron's orbit to shrink, eventually leading it to spiral into the nucleus.

* Emit a continuous spectrum of radiation. This is because the accelerating electrons are producing electromagnetic waves with a wide range of frequencies.

However, these predictions of classical electromagnetic theory are not observed in reality:

* Atoms are stable. Atoms do not collapse due to electrons spiraling into the nucleus.

* Atoms emit specific, discrete wavelengths of light. This is known as line spectra, and contradicts the classical prediction of a continuous spectrum.

These discrepancies led to the development of quantum mechanics, which provides a more accurate description of atomic behavior. Here are some key differences between classical and quantum descriptions of electrons:

* Quantized energy levels: In quantum mechanics, electrons occupy specific energy levels within an atom, rather than continuously radiating energy. They can only transition between these levels by absorbing or emitting photons of specific energies.

* Wave-particle duality: Electrons exhibit wave-like properties, meaning they can be described by a probability wave function, which describes the likelihood of finding the electron at a particular location and time. This wave function is quantized, and the allowed values correspond to the discrete energy levels.

* Uncertainty principle: It is impossible to simultaneously know both the position and momentum of an electron with perfect accuracy. This principle introduces inherent fuzziness into the description of electron motion, preventing it from spiraling into the nucleus.

Therefore, while classical electromagnetic theory provides a useful framework for understanding many phenomena, it is insufficient to explain the behavior of electrons in atoms. Quantum mechanics is necessary to fully understand the stable nature of atoms and the discrete nature of their emitted light.