Transcript Atomic Structure

Ground vs. Excited State
 Ground State – electrons are
in positions of lowest energy
possible (normal)
 Excited State – electron is in a
temporary position of higher
energy than ground state
 Very unstable; the electron
quickly returns to the ground
state
Compared to a sodium atom in the ground
state, a sodium atom in the excited state
must have
There is not change in the number of
electrons, just their location
A.) a greater number of electrons
B.) a smaller number of electrons
C.) an electron with greater energy
D.) an electron with less energy
Recognizing Ground Vs. Excited
 Am I Excited!?
G  1s22s22p5
A = Ground
E  1s22s12p5
B = Excited
E  1s22s22p63s23p63d4
G  1s22s22p63s23p64s1
G  1s22s22p63s23p64s23d6
E  1s22s22p63s23p64s23d105s1
Which electron configuration is possible
for a nitrogen atom in the excited state?
A.) 1s22s22p3 Ground
B.) 1s22s22p23s1
C.) 1s22s22p4
Oxygen
D.) 1s22s22p2
Carbon
Which electron configuration represents
a potassium atom in the excited state?
A.) 1s22s22p63s23p3
Phosphorous
B.) 1s22s22p63s13p4
Excited Phosphorous
C.) 1s22s22p63s23p64s1
D.) 1s22s22p63s23p54s2
Chlorine
Changes in Electron Energy
 Electrons must
gain energy to
transition to the
excited state
 Electrons release
energy
transitioning back
to the ground
state
Ground 
Excited
Excited
 Ground
e- gains energy
e- releases
energy
Be
Which electron transition represents
a gain of energy?
The farther from the nucleus the
greater the energy
A.) from 2nd to 3rd shell
B.) from 2nd to 1st shell
C.) from 3rd to 2nd shell
D.) from 3rd to 1st shell
Emission of Energy
 All elements have a unique energy level
system (due to differences in nuclear
charge)
 The amount of energy released when
returning from excited state to ground
state is different for each element
 Multiple transitions are possible
 Some of the energy released has
wavelengths within the visible light range
Atomic Spectra
 If the light emitted by an electron is
passed through a prism it produces an
atomic emission spectrum
 The results are lines of light at specific
energy levels
 The atomic spectra of a given element is
unique and can be used to identify an
element
Na
K
Ca
Cu
Ba
The characteristic bright-line spectrum
of an element occurs when electrons
A.) move from lower to higher energy levels
B.) move from higher to lower energy levels
C.) are lost by a neutral atom
D.) are gained by a neutral atom
High to low releases energy
The characteristic spectral lines of
elements are caused when electrons in
an excited atom move from
A.) lower to higher energy levels, releasing
energy
B.) lower to higher energy levels, absorbing
energy
C.) higher to lower energy levels, releasing
energy
D.) higher to lower energy levels, absorbing
energy
Electron X can change to a higher
energy level or a lower energy level.
Which statement is true of electron X?
A.) Electron X emits energy when it changes to
a higher energy level.
B.) Electron X absorbs energy when it changes
to a higher energy level.
C.) Electron X absorbs energy when it changes
to a lower energy level.
D.) Electron X neither emits nor absorbs
energy when it changes energy level.
Which of the following quantum leaps
would be associated with the greatest
energy of emitted light?
A.) n = 5 to n = 1
B.) n = 4 to n = 5
C.) n = 2 to n = 5
D.) n = 5 to n = 4
The atomic emission spectra of a
sodium atom on Earth and of a sodium
atom in the sun would be
A.) the same
B.) different from each other
C.) the same as those of several other
elements
D.) the same as each other only in the
ultraviolet range
Each element has a unique spectra that is
unchanged based on locations
Which two elements are present in
the unknown spectra below?
A.) Li & H
B.) Li & Na
C.) H & He
D.) Li & He
Electron Cumulative Quiz
 Electron Configurations:
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Arrows
Shorthand spdf
Noble Gas
Bohr
Valence Electrons
Lewis Dot Diagrams
Ground Vs. Excited State
Bright Line Spectra