“State of Mind”
• Ground State- the energy level that an
electron normally occupies. (periodic table)
• Excited State- a higher-energy level is
occupied by the electron(s), less stable state.
Felix Baumgartner 24 miles above Earth
Felix Jumps At 128k feet! Red Bull Stratos - freefall from the edge of space - YouTube
Whoa Baby
Electrons can gain or lose energy to move to
different energy levels.
Absorption and Release of Energy by an electron
1) When an electron absorbs a specific amount of energy
(known as quanta or quantum of energy), the electron
becomes excited and moves or “jumps” to a higher energy
orbital.
2) When the electron “jumps” to a higher energy level or
orbital it is said to be in the excited state.
3) When the electron releases this excess energy, it releases
the energy as a photon of light and falls to the ground
state.
4) The color light that is emitted or released is determined by
how many orbitals and which orbitals the electron “falls”
Flame Test
Atomic Emission Animation - YouTube
1. Electron absorbs
energy from the flame
and travels to a higher energy
state.
Light Photon
2. Electron falls back down to
a lower orbital and energy state
and releases the energy it absorbed
as light energy.
Aim: What happens when an excited electron “falls” to a
lower energy level?
Flame Test for Cations
Fireworks
Lithium
Sodium
Potassium
Copper
Orbitals
Atomic Emission Animation - YouTube
n=3 -----------------------------------------------------
n=2 ----------------------------------------------------
n=1 ----------------------------------------------------
What element is this?
Explain!
Emission Spectra Creation
The electron in a higher energy state moves down to a lower energy
state and releases excess energy in the form of visible light.
Imagine climbing a ladder and
trying to stand between the
rungs. Unless you could stand
on air, it would not work. When
atoms are in various energy
states, electrons behave in much
the same way.
How can you compare an electron
in its respective orbitals to a person
climbing a ladder?
Bright Line Emission Spectra
How does this happen?
1. “Excited electrons” at higher energy
levels will eventually release the extra
energy and “fall back down” to
ground state conditions.
2. During the “fall back”, energy is
released as Visible Light Energy.
Like a person occupying a step on a ladder,
an electron can only occupy an orbital.
A person can transition or “jump and fall”
between steps, but they
cannot stand mid air between steps.
An electron behaves in a similar fashion,
it just depends on the loss or gain of energy.
Where do we get the color spectrum?
• This emitted energy comes in the form of
photons (light energy).
• The light has a very specific wavelength that
depends on the electron's energy when the
photon is released.
Why do we only see a “flash” of light?
Bright Line – Emission Spectra
The Emission Spectrum
A hot, transparent gas produces an emission line
spectrum- a series of bright spectral lines
against a dark background.
How does the lab work?
Atomic Spectra of Noble Gases
Spectral Lines
Helium
Neon
Argon
A bright line spectrum is produced when
an electron falls from a higher energy
state to that of a lower energy state.
How would you compare
different element’s spectral
line patterns to an individual’s
DNA?
Unknown DNA Sample
Match
The bright-line spectra for three elements and a mixture of elements are
shown below.
1)
2)
3)
Identify all the elements in the mixture.
Explain, in terms of both electrons and energy, how the bright-line spectrum
of an element is produced.
State the total number of valence electrons in a cadmium atom in the ground
state.
The Sun is a giant nuclear reaction.
How do we know that the gas we see is made up of Helium? Sun Video
Bohr Model vs. Wave Mechanical Model
Quantum Mechanics: The Structure Of Atoms - YouTube
Bohr Model
Wave Mechanical
When a Hydrogen e– was
excited, the light
emitted was found to
be composed of
regularly spaced lines.
Each element has a
Visible-line spectrum.
An atomic orbital is the
region of space around
the nucleus where the
probability of locating
an e– with a given
energy is greatest.
Let there be light!
When moving to a higher energy level
(by heat or electricity) an electron
absorbs energy.
Energy is released in the form of light
when the electron returns to the lower
energy level.