# What were the contributions of de Broglie, Hund, and Pauli to our understanding of the atom?

##### 1 Answer

Jul 7, 2017

#### Answer:

See below.

#### Explanation:

**de Broglie** - particle-wave duality

Showed that electrons can act as waves, where their wavelength is inversely proportional to the electron's momentum,

#lambda=h/p# ,where:

#lambda# = de Broglie wavelength in#m# #h# = Planck's constant (#6.626*10^-34Jcdot s# )#p# = electron's momentum in#kg cdot m//s#

**Hund** - Hund's rule of maximum multiplicity

An orbital in a subshell tends to fill with one electron before it gets two electrons, and these electrons in singly occupied orbitals ought to have the same spin.

[NOTE: exceptions occur when the orbitals get big enough.]

**Pauli** - Pauli's exclusion principle

Two electrons in the same orbital cannot have the same set of four quantum numbers:

- principal quantum number (
#n# )- orbital angular momentum quantum number (
#l# )- magnetic quantum number (
#m_l# )- spin quantum number (
#m_s# ).If both were to reside in the same orbital, they automatically have 3 identical quantum numbers, so their spins must be opposite.