Download Chem20u2(5.2) - Mr. Searcy Chemistry 20

Chemistry 20
Name: _____________
Unit II: Atoms and Elements
5.2 Quantum Theory and the Atom
Pgs. 127-134
I. The learning objectives for this section are:
1. Define and give an example of: ground state, quantum mechanical model of
the atom, atomic orbital, principal energy level, energy sublevel.
2. Summarize the contributions made by Bohr, de Broglie, Heisenberg, and
Schrodinger.
3. Compare the Bohr and quantum mechanical models of the atom.
4. Explain the impact of de Broglie’s wave-particle duality and the
Heisenberg uncertainty principle on the modern view of electrons in atoms.
5. Identify the relationships among a hydrogen atom’s energy levels,
sublevels, and atomic orbitals.
II. The following questions will help to cover these objectives as you read through
the section. Briefly answer each question.
1.
What is meant by quantized energy?
2.
What did Bohr propose?
3.
Differentiate between ground state and excited state.
4.
Describe the Bohr model of the atom.
5.
a) What did Bohr suggest happened when an electron fell from a higher
energy level to a lower energy level within an atom?
b) Look up and write down the meaning of “photon”.
6.
Describe a real-life analogy which helps to describe the energy states that
an electron can have in an atom.
7.
What two shortcomings caused scientists to finally reject Bohr’s model of
the atom?
8.
a) Breifly describe the de Broglie’s revolutionary concept involving the
characteristics of moving particles.
b) What did the de Broglie equation illustrate?
c) Explain why we cannot see the wavelengths emitted by everyday objects
such as people, baseballs, etc.
9.
What problem occurs when one tries to determine the exact position of an
electron in an atom?
10.
What is the Heisenberg uncertainty principle?
11.
a) What did Schrodinger do?
b) Why was Schrodinger’s model of the atom better than Bohr’s model of
the atom?
c) What is Schrodinger’s model of the atom called?
12.
a) What does the Schrodinger equation help to predict?
b) What is the probability that an electron will be found within an atomic
orbital?
13.
Explain the concept of an atomic orbital.
14.
a) What is the purpose of principal quantum numbers?
b) What is another thing do principal quantum numbers specify?
15.
Describe the relationship between energy sublevels and principal energy
levels.
16.
a) What letters are used for sublevels?
b) State and sketch the shape of an “s” orbital.
c) State and sketch the shape of a “p” orbital.
d) How many electrons can occupy a single orbital?
17.
Complete the following chart.
Principal
quantum
number (n)
1
2
3
4
Sublevels
(types of
orbitals
present)
Number of
orbitals
related to
sublevel
Total number
of orbitals
related to
principal
energy level
(n2)
Total number
of electrons
related to
principal
energy level
(2n2)