Chem Exam 2: Quantum Numbers and Atomic Orbitals

Principal Quantum Number (n)

Determines the spatial extent (volume/size) of the orbital; denotes the different “shells”; determines the energy of a 1-electron atom or ion; must be positive integers (n=1,2,3,…)

Angular Momentum Quantum Number (\ell)

Determines the shape of the orbital; denotes the subshells; its values are 0,…,(n−1)

Magnetic Quantum Number (m_\ell)

Determines the number of orbitals in each subshell; defines the orientation of orbitals; its values are integers from −ℓ,…,0,…,+ℓ

Electron Spin Quantum Number (m_s)

Describes the electron spin; values are ±1/2

Atomic Orbitals

The first three quantum numbers describe the orbital; they are waves that describe the likely position of electrons

Orbital Energy Degeneracy

Occurs when atomic orbitals have the same energy; for 1-electron atoms/ions, orbitals with the same n are degenerate

Radial nodes

Spherical nodes, where the number of radial nodes =n−ℓ−1

Angular nodes

Planar nodes (for this course), where the number of angular nodes =ℓ

Nodes

Locations within a wave where the amplitude is equal to zero at all times