Download Study Guide Chapter 5

Study Guide Chapter 5
1. Explain Heisenberg’s Uncertainty Principle as it pertains to atomic theory.
 When attempting to measure the position and momentum (velocity) of
an electron there will always be some uncertainty in each
measurement.
2. What are the shapes of “s” and “p” orbitals?
 s orbitals are spherical and p orbitals have dumbbell shape.
3. Describe and give the name for our modern model of the atom.
 The sum total of the various paths of electrons, traveling at very high speeds,
is described as the electron cloud. This “electron cloud” is an area of
negative charge surrounding the nucleus that shows areas where an electron
is “likely” to be found.
4. What is the probability of finding an electron within a defined area of space
within our modern model of the atom?
 90%
5. Differentiate between paired and unpaired electrons.
 Paired electrons are electrons within the same orbital. Unpaired
electrons are electrons that are alone within an orbital.
6. What element has an electron configuration which ends in 4p4 ?
 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4 contains 34 electrons and therefore
contains 34 protons which is selenium (Se).
7. How many electrons can occupy a 4f orbital?
 2 electrons. All orbitals can only hold at the most two electrons.
8. How many sublevels are present in the n = 9 energy level?
 9 sublevels
9. How many orbitals are present in the n = 7 energy level?
 (7)2 = 49 orbitals
10. How many electrons are present in the n = 12 energy level?
 2(12)2 = 2(144) = 288 electrons needed to fill the 12th energy level
11. How many electrons can occupy each of the sublevels “s”, “p”, “d”, and “f”.
 s sublevels can hold 2 or less electrons
 p sublevels can hold 6 or less electrons
 d sublevels can hold 10 or less electrons
 f sublevels can hold 14 or less electrons
12. Give the electron configuration, orbital filling diagram, and electron dot diagram
for arsenic (Z=33).
 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3
This shows only the orbital filling diagram for the last sublevel (4p3 ). The rest of
the sublevels (1s2 2s2 2p6 3s2 3p6 4s2 3d10) would be filled with electrons.
↑
↑
↑
As
13. What is the name and letter designation for the first quantum number?
 Principle Quantum Number (n)
14. What do each of the four quantum numbers designate?
 first quantum number = energy level (distance from the nucleus)
 second quantum number = sublevel (orbital shape)
 First quantum number = orbital
 First quantum number = electron spin
15. What do the +1/2 and –1/2 values of the fourth quantum number designate?
 The up and down spins of the electron within the orbital
16. How do the electrons spin in a d sublevel with 5 electrons?
 They all spin in the same direction.
17. How do the electrons spin in a d sublevel with 10 electrons?
 Half spin up and half spin down.
18. Describe the concept of wave – particle duality.

There are instances when particles behave as waves and instances when
waves behave as particles.
19. What does the Schrodinger Equation allow us to predict?
 The probability distribution of electrons.
20. What are each of the following scientists most associated with?
(a) Niels Bohr
 Created a model of the atom that assigned specific energies
to electrons
(b) Louis De Broglie
 Increased our understanding of the wave – particle duality
of light.
(c) Erwin Schrödinger
 Developed an equation that allowed for the quantum –
mechanical (electron cloud) model of the atom to account
for probability.
21. What did the double – slit experiment support?
 The concept of wave – particle duality.