Download Chapter 2 Test Review - Mercer Island School District

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Answers for Chemistry 1 Atomic Theory Quiz Review
1.
Name Each Scientist from the Democritus philosophers to Bohr. Describe their models, draw a
picture, and state the theory
Use the chart below
Name
Model
Picture
Properties being
Measured
Greek
Earth, Wind, Fire,
None, Only Limited
Philosopher Water
Observations
Matter could be endlessly divided
Democritus the smallest particles of matter that
could not be further divided
That different types of atoms existed for
every type of matter.
Atomos: “uncuttable
Dalton
•
•
•
Thomson
All matter is made up of atoms.
Atoms are indestructible and
cannot be divided into smaller
particles. (Not currently true)
All atoms of one element are
exactly alike, but they are
different from atoms of other
elements. (Not currently true)
Atoms were not just neutral spheres,
but are composed of electrically
charged particles.
Atoms were composed of a positive
sphere (the pudding) and had negatively
charged particles called electrons
(plums) embedded into the pudding.
Rutherford Rutherford’s Model: An atom is made
of a small, positively -charged , dense
nucleus and negative “empty space”
called the electron cloud.
Only Limited
Observations
The size of Objects
Observed the
works of other
scientists such as
Law of
Conservation of
Matter and the
Law of Multiple
Proportions.
The Cathode Ray
Tube Experiment
shows negative
charges (electrons)
moving towards a
positive charge
Some Dense,
Positive Alpha
Particles were
deflected from the
dense positive
nucleus.
Most alpha
particles passed
through the atom.
Bohr
Bohr’s Model: Electrons move around
the atom within energy levels and only
a certain amount of electrons can exist
on one energy level at a time.
His experiments
looked at the
emission
spectrum of
atoms, particularly
hydrogen.
Bohr observed that
electrons absorbed
energy, and then
released the
energy in the form
of light.
2.
A balanced equation follows what Law? Give an example of a balanced equation, and explain
why it must be balanced
Balancing demonstrates the Law of Conservation of Matter: Matter cannot be
created or destroyed during a chemical reaction. Matter can only be rearranged.
2AgCl + Na2SO4  Ag2SO4 + 2NaCl
3.
What are Dalton’s three points for his atomic theory. Are they all currently true? Explain.
•
All matter is made up of atoms.
This point is currently true
•
Atoms are indestructible and cannot be divided into smaller particles. (Not
currently true)
Atoms can be divided into protons, neutrons, and electrons
•
All atoms of one element are exactly alike, but they are different from atoms
of other elements. (Not currently true)
Atoms of the same element are different because of isotopes. They differ
in the amount of neutrons or mass.
4.
What are the three classic subatomic particles? What are their charge, location, and mass?
Particle
Charge Location
Proton
+1
Neutron 0
Electron -1
5.
Nucleus
Nucleus
Outside
Nucleus
Mass
(Relative)
1 amu
1 amu
0 amu
What is an element’s atomic number? Mass number? What does the atomic mass tell you?
•
•
•
Atomic Number = The amount of Protons in an atom. This
number is also the amount of electrons in a neutrally charged atom.
Mass Number = The mass of one atom. Protons + Neutrons
Atomic Mass is the Weighted Average Mass of an elements isotopes.
6.
What is an isotope? How is an element’s mass number different from its atomic mass?
•
An isotope is an atom of an element that differs in mass (the amount of neutrons).
Isotopes are chemically identical, but physically different.
7.
Explain why an atom’s atomic mass can be different from each isotope:
• The Atomic Mass is a weighted average of the relative abundance of all the isotopes
that comprise an element.
• The Calculation for atomic mass demonstrates this idea
8.
What is the atomic mass of Copper that has 69.2% Cu-63 and 30.8% Cu-65? Show work/units
• (0.692 x 63amu) + (0.308 x 65amu) = 63.6 amu
9.
What is the relationship between frequency, wavelength, energy and speed?
•
Both Waves move at the same speed
10. List the order of electromagnetic waves from lowest to highest wavelengths, Include Energy and
Frequency.
11.
Which color of light has the highest frequency? Lowest frequency?
• Violet has the highest frequency
• Red has the lowest frequency
12. What evidence told scientists that electrons were located on specific energy levels, rather than
being scattered randomly around the nucleus?
• The emission spectrum. Specific Frequencies of light are observed. The light is
emitted from electrons when they return to the ground state energy level.
•
If all colors of light were of light were observed (as with a rainbow) then Bohr would
have concluded that there were no energy levels
13. An atom emits 3 colors of light, Red, Blue and Violet when excited by an E.M. wave. Draw the
Bohr Model of an atom that shows these colors of light being emitted
• See the “Electron: How does it behave” Notes. This packet covers EM Waves and
the Bohr Model.
14.
Draw a Bohr Model & Lewis Dot model of Phosphorous, Potassium, Neon, Calcium.
• See Lewis and Bohr Worksheet. You should have a stamp on this!
15.
Now Draw a Bohr model for P-31 and Cl-37 including:
• Labeled subatomic particles in correct amounts
• Labeled regions
P-31
Cl-37
16.
What is a valence electron?
• The outermost energy level electrons of a Bohr Model. These are the electrons that
are shown in a Lewis Dot Model. A valence electron in an electron found on the
highest or outermost energy level. An atom can have a maximum of 8 valence
electrons.
17. What is the valence electron pattern that is observed as you move vertically on the periodic table?
Horizontally?
• There are the same amount of valence electrons within a vertical column\
• Valence electrons increase moving left to right.
Fill in the chart.
Symbol
Atomic
Number
Mass
Number
Protons
Neutrons
Electrons
Ne
10
20
10
10
10
Al
13
27
13
14
13
Na
11
21
11
10
11
Draw and label a diagram of each atomic model. .
~
.
A I~CI
~i~.J.\..u
i'4lMt
,,~~~ t.oI\-N-lbv f.tJ\,\ Sc.i~t-rs+a"~ ~
E"J{pui~~+.
. 4. plum pudding model
i
I
)
('J~l4~ iVf
Q, Le.- ....t r ~ 1'1
j
• I
u
..s
I
5. nuclear atomic model
!
1 ~ lvt
1>~"'<t.e
/
~vt~-.)s.
,.
,
i
I
Calculate the atomic mass of each element described below. Then use the periodic table
to identify each element.
32.
Mass (amu)
Isotope
63X
. 62.930
69.17
6SX
64.928
30.83
(~ '2 • q ::, 0
+ _~ (" 4 _' 9 '2. '6
",oM
33.
Percent Abundance
Isotope
,I
0" ~ C1 'l)
'-1 "
V
c.IM-U
o.
Mass (amu)
Percent Abundance
35X
34.969
75.77
37X
36.966
24.23
'S Cc.'6S)
-
,
(3Y ~
>4- (
-
100
L, t"1
~ (p , C( ~ (D
Ct!M..U
~iML1
1­
"-
J
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Chemistry: Matter and Change· Cha pter 4
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Study Guide