electromagnetic spectrum atomic emission spectrum
TRANSCRIPT
Electromagnetic Spectrum
Atomic Emission Spectrum
Atomic Emission Spectrum
Continuous
Spectrum
Glowing Metal
Photoelectric Effect
Bohr Model (review)
• Only works for hydrogen atoms• Electrons don’t move in circles• The energy was right, but not because e-
circle like planets
The Hydrogen Spectrum• The three
groups of lines in the hydrogen spectrum correspond to the transitions of electrons from higher energy levels to lower energy levels
The Bohr Ring Atom
n = 3n = 4
n = 2n = 1
Quantum Mechanical Model
• Louis de Broglie -1924– Matter could move
like a wave– Like standing
waves– The vibrations of a
stringed instrument
Schrödinger Equation
Quantum Numbers
• A set of 4 “numbers” that describe an electron
• Tell us– Energy level– Shape of orbital– Orientation of orbital around nucleus– Spin
Principal quantum number• Principal quantum
number (n) – Energy level of the
electron– 7 energy levels– Correspond to 7
periods (rows) of periodic table
Angular Momemtum Quantum Number
• Energy levels are divided into sublevels called orbitals
• An ORBITAL is a region in space where there is a high probability of finding an electron
Orbitals
• Denoted by the letters
s, p, d, and f
• Each orbital can hold 1 or 2 electrons only!
S orbitalsl = 0
1 orbital per energy level
P orbitals 3 orbitals per energy level
P orbitalsl = 1
3 orbitals per energy level
D orbitalsl = 2
5 orbitals per energy
level
F Orbitalsl = 3
7 orbitals per energy level
Magnetic Quantum Number
Magnetic quantum number (m I)
Gives the axis orientation Tells direction in each shape (x,y,z)
Spin Quantum Number
• Describes the direction the electron is spinning.
Spin Quantum Number
• Describes the direction the electron is spinning.
Electron Configuration
We follow 3 rules to get the correct electron configuration for each atom
1. Aufbau Principle
2. Pauli exclusion Principle
3. Hund’s Rule
Energy Levels in atoms
Sublevels Orbitals
Energy Levels in atoms
Sublevels Orbitals