Download Practice Problems for Chapters 5, 13, 14 - Parkway C-2

Study Guide for Unit I Test
2012
The work on this packet is due on Tuesday 09-11-12 (Blue) and Wednesday 09-12-12 (Red).
Complete all of the work on these questions to prepare for the test on Thursday 09-13-12 (Blue) or
Friday 09-14-12 (Red). You can write on this packet, but there will probably be questions that require
additional paper, please show all of the necessary work and explanation.
Questions 1 - 8 are from the reading of chapter four and the notes given on August 21 or 22,
2012. These notes are on-line as Smart Board notes.
1.
Please complete the following chart.
Particle
Proton
Neutron
Electron
Symbol
Charge
2.
Please complete the table correctly.
Atomic #
Mass #
# protons
Mass (a.m.u.)
# neutrons
# electrons
64
56
1314
15
3.
4.
Symbol (with
charge)
27
56
81
14
Sio
16
(no charge)
18
Give the correct number of each kind of subatomic particle for
a. # protons =
Location
b. # neutrons =
c.
66
30
Zn
# electrons =
The four isotopes of lead are shown below, each with its percent by mass abundance and the
composition of its nucleus. Using these data, calculate the approximate atomic mass of lead.
22.1%
52.4%
5.
6.
There are five different types of isotopes for the element chromium (Cr.) Given the following
information, calculate the average weighted atomic mass. All calculations and logic work must be
shown. The final answer should have the correct number of significant digits and unit.
Isotope
Mass (a.m.u.)
Natural %
Abundance
50
Cr
49.9461
4.35
52
Cr
51.9405
83.79
53
Cr
52.9407
9.50
54
Cr
53.9389
2.36
A particular atom of bromine, atomic number 35, has a mass number of 79.
a. What is the electrical charge of the atom?
b. Give the number of protons, electrons and neutrons for this atom.
7.
The following table describes four atoms. Be able to explain your answer.
Atom A
Atom B
Atom C
Atom D
No. of protons
10
11
11
10
No. of neutrons
11
10
11
10
No. of electrons
10
11
11
10
Explain your answer.
a. Are atoms A and B isotopes of the same element?
b. Are atoms A and D isotopes of the same element?
c. What is the mass number for atom A?
d. What is the mass number for atom D?
e. What is the charge of atom B?
f. What is the atomic number of atom C?
These questions 8 – 13 are from the reading in chapter four and five, and from the presentations
about the scientist (Science Symposium).
8.
Democritus: Democritus coined the word “atomos”, which is where we get the word atom.
a. What did Democritus believe about atoms?
b. What might a picture of his atom look like? Draw it below:
9.
John Dalton: Dalton is known for developing the first atomic theory based on experimentation.
He explained the observable world using models on the atomic level. His postulates state:
a. All ______________ are composed of tiny indivisible particles called atoms.
b. Atoms of the same element are ____________. The atoms of any one element are
____________ from those of any other element.
c.
Atoms of different elements can ____________ mix together or can _____________
combine in simple whole-number _________ to form compounds.
d. Chemical ________________ occur when atoms are separated, joined together, or
______________. Atoms of one element, however, are never changed into atoms of
another element as a result of a chemical reaction (Law of Conservation of Mass).
10.
JJ Thomson: Thomson advanced the understanding of atoms by realizing that they are divisible.
Thomson was the scientist credited with discovering the first fundamental particle (subatomic
particle) within the atom.
a. Label the parts of the cathode ray tube experiment below [use your book or the internet].
b. Refer to the diagram above. Is the beam of electrically charged particles attracted to the top plate
or the bottom plate? What charge does that plate have?
c.
Refer to the diagram and the direction the beam of energy is pulled, your answer to b, what
does this result indicate about the charge of the particles in the beam?
d. What are these particles know as?
e.
Why was it significant that the same results were seen, regardless of type of elemental gas in
the tube or the type of metal used for the electrodes?
f.
Thomson assumed that if there were negative particles, there must be something positive,
too. Therefore, he developed the Plum-Pudding Model of the atom. Draw and label a picture
of the plum-pudding model of the atom below:
11.
Eugen Goldstein: While experimenting with the cathode ray tube, Goldstein observed rays
traveling in the opposite direction as cathode rays. He determined that they must be made of
particles that have an opposite charge than electrons. These positively charged particles are
called _____________.
12.
Ernest Rutherford: Alpha (α) particles were used by Rutherford in the Gold Foil Experiment.
Alpha are a Helium nucleus, which means they are heavy and carry a positive two charge.
a.
Based on Thomson’s Plum Pudding model of the atom, what was Rutherford expecting to
see when he shot the alpha particles at the gold foil? Why?
b.
What were the actual results of the experiment? Why was it a surprise?
13.
c.
What was Rutherford able to conclude about the structure of the atom?
What important part of the atom was discovered because of this experiment?
d.
Rutherford’s model of the atom is called the nuclear model of the atom. Sketch a picture
of Rutherford’s model below: (be sure to label the location of the protons and neutrons in
the atom)
Describe as best you can the problem with Rutherford’s model and what Bohr, De Broglie,
Heisenberg, and Schrödinger proposed and explained using mathematics.
For Questions 14 – 25, refer to the Colorimeter Laboratory Experience and the use of the formulas
from the chapter five material and homework problems:
c = λυ
c = 3.00 x 108 m
E = hυ
h = 6.6262 x 10-34 Js
y = mx + b
s
14.
Blue light has a __________________ energy and _______________ frequency, and a
________________ wavelength, when compared to red light.
15.
Why is a red light used in a dark room?
16.
In general, as the wavelength of light increases, the frequency ___________________.
17.
What is the frequency of light that has a wavelength of 565 nm? What is the color of this light?
18.
Calculate the energy of a light that has a frequency of 4.50 x 10 14 s-1.
19.
If the energy of some wave from the electromagnetic spectrum is 6.73 x 10 -19 J, what is its
frequency? What is its wavelength? What type of radiation is this?
20.
List the colors that make up the visible light in order of increasing energy.
increasing energy
21.
Sketch a basic electromagnetic spectrum including x-rays, visible light, ultraviolet, gamma rays,
infrared, radio waves, microwaves.
freq low
freq high
energy low
energy high
22.
When a cesium salt is heated in a flame, a photon of light with energy of 4.3 x 10 -19 J, which is a
frequency of 6.4 x 1014 s-1 and a wavelength of 4.6 x 10-7 m (460 nm) is emitted. On the basis of
this information and the following diagram, what color would be expected for the cesium flame?
14
7.5 x 10
Violet
 = 400 nm
14
Frequency,  (s-1)
6.0 x 10
Blue
Green
500 nm
Yellow
5.0 x 1014
Orange
600 nm
4.3 x 1014
Red
700 nm
23.
If a light of 470 nm (blue) is directed at a red solution, and then directed at a blue solution,
which solution would demonstrate more transmittance of the blue light? Explain your answer.
24.
In the Spectro-vis lab, as the red colored solution is diluted the absorbance of the blue light was
_____________. Why was blue light directed at the red solution?
25.
In the Spectro-vis lab, the positive slope of the linear graph, showed that as concentration (x)
increased, the absorbance (y) ________________.
26.
The equation y = mx + b can solve for concentration (x) or the absorbance (y), as long as the m
(_____________) and b (______________) are known from the linear graph.
For Questions 27 – 35, refer to the material describing how to write electron configurations,
orbital filling diagrams, and electron dot diagrams to complete the following questions.
27.
What is the maximum number of electrons possible in the first, second, third, and fourth energy
levels of atoms? The letter n= means the number of the energy level
n = 1 __________ # en = 2 __________ # en = 3 __________ # en = 4 __________ # e-
28.
Determine which of the following designations are invalid (explain why)?
a.
4s
b.
3f
c.
2d
d.
3d
29.
Write the complete electron configuration for the element Einstenium (Es), #99.
30.
Write the electron configuration for Tin (Sn # 50), how many energy levels does Tin have?
31.
Determine the number of valence electrons (e-) for each of the following atoms. What is the
common charge of this element when it becomes an ion?
# valence e-/electon-dot
Charge
Ion Symbol
a.
Ca
b.
Zn
c.
N
d.
Xe
32.
Write the electron configuration for the element Manganesse #25.
b.
Draw the orbital filling diagram for Manganesse.
c.
Draw the electron dot diagram for Manganesse.
33.
Write the abbreviated electron configuration for Antimony (Sb) #51. Draw the orbital filling
diagram. Give the electron dot diagram.
34.
What is the maximum number of electrons that can be in the sublevel
s = _________
p = _________
d = _________
f = _________
35.
An atom of an element has two electrons in the first energy level and five electrons in the second
energy level. Write the electron configuration for this atom and name the element. How many
unpaired electrons does an atom of this element have?
36.
Which
a.
b.
c.
d.
electron transition results in the emission (release) of energy?
3d to 3s
5p to 4p
2s to 2p
6s to 2s
Using a – d arrange the ones from high energy release to lowest energy release (may even be some
that absorb energy)
37.
Picture two hydrogen atoms. The electron in the first hydrogen atom in in the n = 1 energy level.
The electron in the second atom is in the n = 4 energy level.
a.
Which atom has the ground state electron configuration?
b.
Which atom can emit electromagnetic radiation (energy)?
c.
In which atom is the electron in physically larger orbital?
d.
Which atom has the lowest potential (positional) energy?
38.
Remembering the Gas Tube demonstration with the diffraction gradient glasses and the
Movie on Light, explain what occurs when a gas tube filled with only one type of element emits
light (atomic emission).
Describe what changes occur as heat or electricity is added. Give details and use specific terms
such as ground state, excited state, electrons, P.E., K.E., quantum leap, quanta, wavelength,
frequency, energy, color of light, etc.
Please understand that these are examples of possible questions for the test, but it is very important
that you . . .
Know / Review all the terminology from Chapters 4 and 5 Common language is important in all
types of questions (matching, multiple choice, lengthy calculation and explanation.)
Review the assigned homework problems. Review the main (basic) scientist that contributed to
the current Atomic model. Study your notes, homework assignments, and the laboratory reports
to accomplish a more thorough preparation. In addition, you may want to view the videos on the
Resources Link to prepare as thoroughly as possible.