Download Chapter 2 Test Review - Mercer Island School District

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Answers to the Honors Chemistry 1 Atomic Theory Quiz Review/Practice Quiz
1.
Name Each Scientist from the Greek philosophers to Bohr. Describe their models, draw a picture,
and how their experiment proved their point by specifying what properties were being measured.
Use the chart below
Name
Model
Picture
Properties being
Measured
Greek
Earth, Wind, Fire,
None, Only Limited
Philosophers 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’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.
Bohr
2.
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.
Balance: AgCl + Na2SO4  Ag2SO4 + NaCl and explain why it must be balanced
2AgCl + Na2SO4  Ag2SO4 + 2NaCl
Balancing demonstrates the Law of Conservation of Matter: Matter cannot be
created or destroyed during a chemical reaction. Matter can only be rearranged.
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? List each respective 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? Write the
Isotope notation for an element with the atomic number 6 and a mass number of 14. How many
neutrons does this isotope have?

An isotope is an atom of an element that differs in mass (the amount of neutrons).
Isotopes are chemically identical, but physically different.

There are 8 neutrons in this isotope.
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? Do the equation
including units.
 (0.692 x 63.0amu) + (0.308 x 65.0amu) = 63.6 amu
9.
Lithium has an atomic Mass of 6.94 amu. What is the percent abundance of the two isotopes (Li 6
and Li 7) that make up Lithium?
 6.94 amu = (6 amu [x]) + (7 amu [1-x])
i. % abundance for Li 6 = 6%
ii. % abundance for Li 7 = 94%
10.
What is the relationship between frequency, wavelength, energy and speed?

11.
Both Waves move at the same speed
List the order of electromagnetic waves from lowest to highest wavelengths
12.
Which color of light has the highest frequency? Lowest frequency?
 Violet has the highest frequency
 Red has the lowest frequency
13. 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
14. An atom emits 3 colors of light, Red, Yellow 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.
15.
Draw a Bohr Model AND Lewis Dot diagram of Phosphorous and Potassium.
 See Lewis and Bohr Worksheet. You should have a stamp on this!
16.
Now Draw a Bohr model for P-31 and Cl-35 including:
 Drawn and Labeled subatomic particles in correct amounts
 Labeled regions (nucleus and energy levels)
15p
16n
17p
18n
17. What is a valence electron? What is the valence electron pattern that is observed as you move
vertically on the periodic table? Horizontally?
 A valence electron in an electron found on the highest or outermost energy level. An
atom can have a maximum of 8 valence electrons.
 Threre are the same amount of valence electrons within a vertical column\
 Valence electrons increase moving left to right.
18.
Fill in the chart.
Symbol
Atomic
Number
Mass
Number
Protons
Neutrons
Electrons
14. Ne
10
20
10
10
10
15. Al
13
27
13
14
13
16. Na
11
21
11
10
11