2) The Quantum Numbers - N3.pdf - Quantum Model and Quantum...

Quantum Model and
Quantum Numbers

• Quantum Mechanics – the branch of physics that
uses mathematical equations to describe the wave
properties of subatomic particles.
• Orbital – a wave function that predicts an
electron’s energy and location within an atom.
Quantum Numbers
• Four numbers used to describe a specific
electron in an atom.
• Each electron has its own specific set of quantum
numbers.
Quantum Model of the Atom

The First Quantum Number
• AKA principal quantum number, Symbol “n”
• Indicates the energy level and distance from the
nucleus of an electron (same as period number)
• Higher n → farther from nucleus and greater energy
• n = 1, 2, 3… (always a positive whole number)
• If an electron’s principle quantum number
decreases, energy is emitted

• The first quantum number also helps recognize how
many electrons may reside in that shell
• Using the formula 2?
2
will indicate how many
electrons per shell
• When ? = 1, 2 1
2
= 2 . Therefore there are 2
electrons in a full first shell
• When ? = 2, 2 2
2
= 8
• When ? = 3, 2 3
2
= 18
• When ? = 4, 2 4
2
= 32
• When ? = 5, 2 5
2
= 50