1. Excited Gases & Atomic Structure

2. Electromagnetic Spectrum
 •  = c = 3.00 x 108 m/sec

3. Electromagnetic Spectrum
Short wavelength -->
high frequency
high energy
increasing frequency
increasing wavelength
Long wavelength -->
small frequency
low energy

4. Quantization of Energy
Max Planck ( )
An object can gain or lose energy by absorbing or emitting radiant energy in QUANTA.
Energy of radiation is proportional to frequency
E = h • 
h = Planck’s constant = x J•s

5. Atomic Line Emission Spectra and Niels Bohr
Bohr’s greatest contribution to science was in building a simple model of the atom. It was based on an understanding of the SHARP LINE EMISSION SPECTRA of excited atoms.
Niels Bohr
( )

6. Atomic Spectrum LecturePLUS Timberlake An atomic spectrum consists of
lines of different colors formed when light from a heated element passes through a prism
photons emitted when electrons drop to lower energy levels
Basic Chemistry Copyright © 2011 Pearson Education, Inc.
LecturePLUS Timberlake

7. Electron Energy Levels
Electrons are arranged in
specific energy levels that
are labeled n = 1, n = 2, n = 3, and so on
increase in energy as n increases
have the electrons with the lowest energy in the first energy level (n=1) closest to the nucleus
Basic Chemistry Copyright © 2011 Pearson Education, Inc.
LecturePLUS Timberlake

8. Energy Level Changes LecturePLUS Timberlake An electron
absorbs photons of a specific energy to “jump” to a higher energy level
falls to a lower energy level by emitting photons of a specific energy
Basic Chemistry Copyright © 2011 Pearson Education, Inc.
LecturePLUS Timberlake

9. Energy Emitted LecturePLUS Timberlake
When electrons drop from a higher level to the first level, second level, and third level, photons of ultraviolet light, visible light, and infrared are emitted (not to scale).
Basic Chemistry Copyright © 2011 Pearson Education, Inc.
LecturePLUS Timberlake

10. Line Spectra of Other Elements
Figure 7.9

11. Line Emission Spectra of Excited Atoms
High E
Short 
High 
Low E
Long 
Low 
Visible lines in H atom spectrum are called the BALMER series.

12. n (major) ---> energy level or shell l (angular) ---> subshell
QUANTUM NUMBERS
The shape, size, and energy of each orbital is a function of 3 quantum numbers:
n (major) ---> energy level or shell
l (angular) ---> subshell
ml (magnetic) ---> orbital within a
subshell

13. Symbol Values Description
QUANTUM NUMBERS
Symbol Values Description
n (major) 1, 2, 3, .. Orbital size and energy where E = -R(1/n2)
l (angular) 0, 1, 2, .. n-1 Orbital shape or type (subshell)
ml (magnetic) -l..0..+l Orbital orientation
# of orbitals in subshell = 2 l + 1

14. Each shell has a number called the PRINCIPAL QUANTUM NUMBER, n
Shells & Subshells
Each shell has a number called the PRINCIPAL QUANTUM NUMBER, n
The principal quantum number of the shell is the number of the period or row of the periodic table where that shell begins.

15. Energy Levels
n = 1
n = 2
n = 3
n = 4

16. increase in energy as n increases maximum number of electrons = 2n2
Energy Levels
quantum numbers n = 1, 2, 3, 4, 5, 6, 7
increase in energy as n increases
maximum number of electrons = 2n2
Basic Chemistry Copyright © 2011 Pearson Education, Inc.

17. Sublevels contains electrons with the same energy
is found within each energy level
is designated by the letters s, p, d, or f

18. Number of Sublevels
The number of sublevels in an energy level is the same as the principal quantum number, n.
Basic Chemistry Copyright © 2011 Pearson Education, Inc.

19. Shells and Subshells When n = 1, then l = 0 and ml = 0
Therefore, in n = 1, there is 1 type of subshell
This subshell is labeled s
Each shell has 1 orbital labeled s, and it is SPHERICAL in shape.

20. s Orbitals An s orbital (l = 0)
has a spherical shape around the nucleus
increases in size around the nucleus as the energy level n value increases
is a single orbital found in each s sublevel
All s orbitals have spherical shapes that increase in volume at higher energy levels.
Basic Chemistry Copyright © 2011 Pearson Education, Inc.

21. p Orbitals A p orbital (l = 1) has a two-lobed shape
is one of three p orbitals that make up each p sublevel, each aligned along a different axis
increases in size as the value of n increases
Basic Chemistry Copyright © 2011 Pearson Education, Inc.

22. Types of Atomic Orbitals
Figure 7.15, page 275

23. Sublevels and Orbitals
Each sublevel consists of a specific number of orbitals.
an s sublevel contains one s orbital
a p sublevel contains three p orbitals
a d sublevel contains five d orbitals
an f sublevel contains seven f orbitals
Basic Chemistry Copyright © 2011 Pearson Education, Inc.

25. Each shell has subshells QUANTUM NUMBER, ld p

26. Orbitals (m) No more than 2 e- assigned to an orbital
Orbitals grouped in s, p, d (and f) subshells
s orbitals
p orbitals
d orbitals

27. ORBITALS

28. Electron Capacity
The total number of electrons in all the sublevels adds up to give the maximum number of electrons (2n2) allowed in an energy level.
Basic Chemistry Copyright © 2011 Pearson Education, Inc.

29. d Orbitals l = 0, 1, 2 (s, p, d) When n = 3, what are the values of l?
and so there are 3 subshells in the shell.
For l = 0, ml = 0
---> s subshell with single orbital
For l = 1, ml = -1, 0, +1
---> p subshell with 3 orbitals
For l = 2, ml = -2, -1, 0, +1, +2
---> d subshell with 5 orbitals

30. f Orbitals For l = 3, ml = -3, -2, -1, 0, +1, +2, +3
When n = 4, l = 0, 1, 2, 3 so there are 4 subshells in the shell.
For l = 0, ml = 0
---> s subshell with single orbital
For l = 1, ml = -1, 0, +1
---> p subshell with 3 orbitals
For l = 2, ml = -2, -1, 0, +1, +2
---> d subshell with 5 orbitals
For l = 3, ml = -3, -2, -1, 0, +1, +2, +3
---> f subshell with 7 orbitals

31. Orbitals
An orbital
is a three-dimensional space around a nucleus where an electron is found most of the time
has a shape that represents electron density (not a path the electron follows)
can hold up to two electrons
contains two electrons that spin in opposite directions
Basic Chemistry Copyright © 2011 Pearson Education, Inc.

33. “Your Best Friend”
Periodic table