Download Chapter 5: QUANTUM THEORY AND THE ATOM

NAME ____________________________________________________
PERIOD _____________
DATE ____________________________
Chapter 5: QUANTUM THEORY AND THE ATOM
Bohr’s Model of the Atom
Remember that the atomic emission spectra for hydrogen is ___________________________. It is made up of
certain ___________________________ of _________________________. Scientists wanted to know _________
this was. In _____________ a Danish physicist named _________________________ came up with a model for
the ____________________ atom that answered this question. His model ________________ predicted the
_____________________________ of the lines in _____________________ atomic emission ________________.
Energy states of hydrogen: ______________ proposed that the hydrogen atom has only certain _______________
energy ________________. The lowest _____________ energy _________________ of an ________________ is
called its ________________ state. When an atom ____________energy it is said to be in an _________________
state. Bohr proposed that the _____________________ in a hydrogen ____________ moves around the nucleus
in certain _________________ orbits. The smaller the electron’s _________________, the ____________ the
atom’s energy ________________, or energy ______________. The opposite is also true. The larger the electron’s
____________________, the ______________ the atom’s energy ___________, or energy __________. A
hydrogen ________ can have many different _____________ states, although it has only _________ electron.
Bohr assigned a number, ________, called a _____________number, to each ____________________. The first
_____________, the one ________________ to the _____________ has a ________________ number of n = 1.
The hydrogen line spectrum: When energy is added the electron in an atom rises to an ________________ state.
We can calculate the change in ____________ between two ______________ levels using the following equation:
We can use the following equation to calculate the energy of a quantum, the energy of a photon, or the energy
difference between two levels:
E = ____________________
h = Planck’s constant = ________________________
c = speed of light = ___________________________
λ = _____________________
Ex #1) A green light of wavelength 489 nm is observed in the emission spectrum of hydrogen. Calculate the energy
difference between the two states that are responsible for this line.
Ex #2) The energy of one photon is 5.67 x 10-19 J. What is the length of the wavelength observed?
We can use the following equations to calculate the difference in energy between two states or the wavelength:
ΔE = ________________________
ni = _________________________
RH = ________________________
nf = _________________________
nlow = _______________________
λ = _________________________
nhigh = _______________________
Ex #1) Calculate the wavelength for the electron orbit transition between ni = 3 and nf = 2.
Since only certain atomic __________________ are possible, only certain __________________ of
electromagnetic __________________ can be ______________________. Keep in mind that the ______________
levels are _____________ evenly spaced.
Bohr’s model was good but it only explained the atomic _____________ spectra of the _______________ atom.
The Quantum Mechanical Model of the Atom
In ____________, a French physics student named _________________ explained the _____________ energy
______________ of Bohr’s model. He explained that __________________ can act like ________________. He
showed that ____________________ on circular ________________ can only have _____________ numbers of
_______________________.
de Broglie equation: de Broglie predicted that all moving ________________ have ____________ characteristics.
de Broglie knew that if an _________________ acted like a _____________ and was restricted to certain
________________ orbits that only certain _________________, frequencies, and _______________ are possible.
To show this idea de Broglie came up with the following equation called the Particle Electromagnetic-Wave
Relationship:
λ = ______________________
h = Planck’s constant = __________________________
m = _____________________
ν = ______________________
The Heisenberg uncertainty principle: German physicist, __________________, showed that it is ______________
to ________________ any object without _________________ that ________________. The Heisenberg
_______________ principle states that it is impossible to know ________________ both the ____________ and
the _______________ of a particle at the _______________ time. From the Heisenberg uncertainty
_________________ we also understand that we can only know the _______________________ for an
________________ to occupy a certain region around the __________________. In other words, we can’t assign
an exact fixed _____________of an ________________.
The Schrodinger wave equation: In _____________the Austrian physicist ______________________ came up with
an __________________ that showed hydrogen atom’s _________________ acting like a ________________.
The atomic _______________ that has ________________ acting like ___________________ is called the wave
mechanical model of the atom, or the _______________ mechanical model of the _____________. This model
limits an ____________________energy to certain _________________. Each ___________________ to the
Schrodinger ____________ equation is called a wave _____________________. The wave ___________________
predicts the 3D region around the _______________________, called an atomic _______________, where the
electron is most likely to be ____________________. An electron is _______________ likely to be found near the
____________________ of an atom.
Hydrogen’s Atomic Orbitals
Principal quantum number: Remember that ___________ atomic model assigned _____________ numbers to
______________ orbits. Like Bohr’s model, the __________________ mechanical model assigns ____________
quantum ___________ to atomic ______________. The _______________ one is called the __________________
quantum number, _____________, which gives the relative _____________ and _____________ of atomic
orbitals. n specifies the ______________ major ______________ levels, which are each called _______________
energy levels. As n _______________, the _____________ gets _____________, the _________ of the atom
____________________, and the ______________ spends more time farther away from the _______________.
An ________________ lowest principal _________________level is given a principal _________________ number
of ________. So when ________________ atom’s single _________________ occupies an orbital with
____________________ the atom is in its ___________________ state.
Energy sublevels: Each ___________________ energy level contains energy _______________, where principal
energy level __________ has ___________ sublevel and principal energy level _______________ has
______________ sublevels. Designated by the symbol ___________. Sublevels are labeled s (_________), p
(________), d (_______), or f (_______) according to the ________ of the atom’s ____________. All _______
orbitals are _____________ and all _______ orbitals are ______________, but not all _____ or _____ orbitals
have the same ___________. Each ____________ can contain, at most, ______ electrons.
Principal energy level 1: (n = 1) Principal energy level _______ corresponds to a _____________ orbital called the
_____________ orbital.
Principal energy level 2: (n = 2) The ________sublevels in principal energy level______ are designated by _______
and _______. The _____ sublevel corresponds to the ____ orbital which is spherical like the 1s __________, but
__________ in ________. The ____ sublevel corresponds to three ___________________________ p orbitals
designated ________, 2py, and __________. The subscripts x, y, and z correspond with the x, y, and z coordinate
___________.
Drawings of the 1s, 2s, and px, py, and pz orbitals:
Principal energy level 3: (n = 3) Consists of 3 _____________ designated ________, 3p, and ________. Each _____
sublevel relates to _________ orbitals of _________ energy.
Drawings of the 5 d orbitals:
Principal energy level 4: (n = 4) Consists of a 4th sublevel called the _______ sublevel. This sublevel relates to ____
f orbitals of _________ energy.
Hydrogen’s First Four Principal Energy Levels
Principal Quantum
Number (n)
Sublevels (Types of
Orbitals) Present
Number of Orbitals
Related to Sublevel
1
2
s
s
p
s
p
d
s
p
d
f
1
1
3
1
3
5
1
3
5
7
3
4
Total Number of Orbitals
Related to Principal
Energy Level (n2)
1
3
9
16
Note that the number of orbitals related to each ______________ is always an _____________ number.
At any given time, the ______________ in a hydrogen ____________ can occupy only ________ orbital. When the
hydrogen atom is in the _____________ state, the ____________ occupies the _______ orbital. Depending on the
____________ available the ____________ can move to the ________ orbital, to one of the 3 _________ orbitals,
or to any other ___________ that is ___________.
Important Points:



Bohr’s atomic model explains hydrogen’s atomic emission spectra from the fact that electrons drop from
higher-energy to lower-energy orbitals. Bohr’s model also assumes that electrons are particles.
The quantum mechanical model assumes that electrons act like waves. This model assumes that electrons
act like particles and waves.
Electrons occupy 3D regions of space around a nucleus called atomic orbitals.
HOMEWORK PRACTICE PROBLEMS
1. What is the wavelength of electromagnetic radiation with a frequency of 5.00 x 1012 Hz?
2. What is the frequency of electromagnetic radiation with a wavelength of 3.33 x 10-8 m?
3. What is the energy of one photon from electromagnetic radiation that has a frequency of 7.230 x 1014 Hz?
4. Which color in the section of visible light on the electromagnetic spectrum has the longest wavelength?
5. Which color in the section of visible light on the electromagnetic spectrum has the most energy?
6. Which color in the section of visible light on the electromagnetic spectrum has the lowest frequency?
7. Which color in the section of visible light on the electromagnetic spectrum has the highest frequency?
8. Calculate the wavelengths for the following electron orbit transitions:
a. ni = 5; nf = 2
b. ni = 4; nf = 2
c. ni = 6; nf = 2
9. Calculate the wavelength and energy per quantum for the electron orbit transition for which nf = 3 and
ni = 5.
10. What do the sublevel designations s, p, d, and f specify with respect to the atom’s orbitals?
11. What is the maximum number of electrons an orbital can contain?
12. What does n represent in the quantum mechanical model of the atom?