Download Quantum Notes

Quantum Theory
Corresponds with your chapter 5
Limitations of the Early
Models
Early models don’t explain
How the electrons were arranged around the
nucleus
Why negatively charged electrons are not
pulled into the positively charged nucleus
Why atoms of elements behave the way they
do
Light can act as waves
or as particles.
Wave Nature of Light
The speed of light (c = 3.00  108 m/s) is the product
of it’s wavelength (λ) and frequency (ν)
c = λν
What is the relationship between
frequency and wavelength?
• A prism separates sunlight into a continuous
spectrum of colors
•The electromagnetic spectrum includes all forms
of electromagnetic radiation
Particle Nature of Light
• The wave model of light cannot explain all of
light’s characteristics; Albert Einstein
proposed in 1905 that light has a dual nature
(wave-like and particle-like)
• Matter can gain or lose energy only in small,
specific amounts called quanta
•A quantum is the minimum amount of
energy that can be gained or lost by an atom
• The atomic emission spectrum of an element is
the set of frequencies of the electromagnetic waves
emitted by the atoms of the element
•Each element’s atomic emission spectrum is
unique, like a fingerprint
Heisenberg Uncertainty
Principle
• It is impossible to know the
position and velocity/momentum
of an electron at any time.
• Because whatever you use to view it
(light or radiation) would change the
position or momentum
Review
Identify the parts of a wave:
A
A
B
C
A
D
Review
Compare the wave and particle
models of light.
Review
Explain the difference between the
continuous spectrum and the
emission spectrum of an element.
Finish spec 20 lab – make color
observations!
Physicists tend to view electrons
as particles, hence the quantum
theory which describes the
behavior of subatomic particles.
Does it take more energy for the
painter to climb to the middle or
to the top rung/stair?
Suppose the painter climbed to
the middle rung/stair and
dropped the paintbrush. Then,
she climbed to the top rung/stair
and dropped the paintbrush.
From which level did the
paintbrush hit the ground with
more energy?
Ground vs. Excited
Ground state is when the electrons are
in the lowest energy levels.
Electrons that have absorbed energy
jump to higher levels and become
excited.
The ground represents the area of the nucleus and energy
increases as you go up.
Which seats in the arena are in more
demand and more expensive?
How does the seating arrangement represent energy
levels?
n = venue
l = section
ml = row
ms = seat
No two people can have the exact same ticket for the exact
same seat!
Take notes on the four quantum numbers:
Principle
Angular
Magnetic
Spin
https://www.khanacademy.org/science/chemistry/electronic-structure-of-atoms/orbitalsand-electrons/v/quantum-numbers
Make a table:
n
orbitals
# e- in orbital
#e- in shell
https://www.khanacademy.org/science/chemistry/electronic-structure-ofatoms/orbitals-and-electrons/v/quantum-numbers-for-the-first-four-shells
Review
What does the principal quantum number
indicate?
What is the maximum number of p orbitals in a
principal energy level?
Another analogy
In addition to the spectra, compounds can be identified
when they are heated in a flame.