This chapter uses quantum theory to describe the modern model of the atom and explain atomic emission spectra. It presents three rules you will use to write electron configurations for atoms: the aufbau principle, the Pauli exclusion principle, and Hund's rule. In this chapter, you will learn how the study of light has contributed to the quantum mechanical model. You will also learn that light is described as packages of energy (quanta or photons) that travel as waves.

In this chapter, you will learn: to summarize the development of atomic theory to explain the significance of quantized energies of electrons to apply the aufbau principle, the Pauli exclusion principle, and Hund's rule in writing electron configurations to calculate the wavelength, frequency, or energy of light, given two of these values to explain the origin of the atomic emission spectrum of an element