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1
Semester 1 2015
Final Exam
Chemistry
2nd Period – Wednesday 12/16 4th Period – Thursday 12/17
7th Period – Friday 12/18
Exam Format 125 Multiple Choice Questions
90 minutes
Semester 1 Units:
Lab Safety, Scientific Method/Graphing, Classification of Matter, Atomic Structure/Electron Configuration, The Periodic Table, and Bonding.
Review all class notes, worksheets, flashcards, activities, labs, and quizzes.
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Question If any of the following happens….
Fire erupts
Someone is hurt
Chemical spill
What should you do first??
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Answer
Notify the instructor!
Question
What is the purpose of the fume hood?
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Answer Ventilation system that is used for
gases/vapors released during a chemical reaction that are not healthy for you to breathe in
Question
What is the proper procedure for disposing of chemical waste?
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Answer It depends on the chemical…
Chemicals must always be disposed of according to teacher’s instructions!
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Question
What are the 5 main steps of the scientific method?
Answer 1. Recognize and identify the problem
2. Develop hypothesis
3. Perform experiment
IV, DV, control group, experimental group, constants
4. Analyze data
5. Make a conclusion
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Question What are two tools you can use to
record your data and display your data?
Answer Data table – used to record data
Graph – used to display data
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Question Define the following:
Independent Variable
Dependent Variable
Answer IV: variable manipulated or changed by
experimenter
IV = I CHANGE
DV: variable that is observed; it is influenced by the IV
DV = DATA
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Question How is the experimental group
different from the control group?
Answer Experimental group: Given the IV or
different variations of the IV
Control group: Not given the IV, left under normal conditions
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Question What are constants?
Answer All other potential independent variables
that can influence your results
Also called control variables
They need to be controlled/kept constant..
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Question One tank of 10 gold fish is fed the normal amount of
food once a day. A second tank of 10 gold fish is fed twice a day. A third tank of 10 gold fish is fed four times a day during a six week study. The fish’s weight is recorded daily.
IV:
DV:
Constant:
Control GRP:
Experimental GRP(s):
Answer One tank of 10 gold fish is fed the normal amount of food once a
day. A second tank of 10 gold fish is fed twice a day. A third tank of 10 gold fish is fed four times a day during a six week study. The fish’s weight is recorded daily.
IV: # of times fed a day
DV: Fish’s weight
Constant: size of tank, type of fish, fish bought from same place, same filter system, same type of food, etc.
Control GRP: fish fed the normal amount of food
Experimental GRP(s): fish fed 2x and fish fed 4x
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Question Which axis does the IV go on? Which axis
does the DV go on?
Answer
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Question What are the two types of pure
substances that are made up of only one type of matter?
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Answer Elements
Ex: GOLD
Compounds
Ex. Water H2O
Question How is a homogenous mixture
different from a heterogeneous mixture?
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Answer Homogenous: Mixture in which the composition is
uniform; constant composition throughout
Heterogeneous: A mixture in which the composition is not uniform throughout
Question Element, compound, homogenous
mixture or heterogeneous mixture?
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Answer Heterogeneous mixture
Question Is burning wood a physical or
chemical change? Explain why.
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Answer Chemical change
New substances are formed!
Question Is melting point a physical or
chemical property? Explain why.
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Answer Physical property
Recording temperature at which a substance is melting does not change the identity of the substance
Question Is dissolving sugar in water a
physical or chemical change? Explain.
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Answer Physical change
You still have sugar and water!
No new substance formed!
Question Next to the statement, identify if it is:
Physical change
Chemical change
Physical property
Chemical property
1. Boiling water _____
2. Rusting ______
3. Ability to burn _____
4. Boiling point _____
5. NaCl Na + Cl ______
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Answer 1. Boiling water – Physical Change
2. Rusting - Chemical Change
3. Ability to burn – Chemical Property
4. Boiling point – Physical Property
5. NaCl Na + Cl – Chemical Change
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Question
How was the nucleus discovered?
Answer He fired a (alpha) particles at a very thin sample of
gold foil
Most of the positive particles went through but a few bounced back at wide angles
They were hitting the small dense region in center – the nucleus!
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Question What is the charge and location of:
Proton
Neutron
Electron
Answer Proton –
positive, nucleus
Neutron – neutral, nucleus
Electron - negative, orbitals/ electron cloud
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Question What is atomic #? What is average
atomic mass? What are these two values for hydrogen?
Answer Atomic # = # of protons in nucleus
Average atomic mass = weighted average of all the masses of an atom’s isotopes
Hydrogen
Atomic # = 1
aam = 1.008
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Question In a neutral atom, the number of
protons always equals the number of ______________________
Answer In a neutral atom, the number of
protons always equals the number of electrons.
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Question The mass number =
________ + _________
Answer The mass number = # protons + # of neutrons
Protons and neutrons are the ones with a significant mass!!
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Question How is the charge of an ion
determined?
Answer Protons – electrons
It is the difference between the protons and electrons
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Question For an atom of Carbon-12, how many:
Protons:
Neutrons:
Electrons:
Answer For an atom of Carbon-12, how many:
Protons: 6 (atomic number)
Neutrons: 6 (mass # - atomic #)
Electrons: 6 (if neutral, equal to the number of protons)
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Question
How is an ion different from an isotope?
Answer Ion is an atom with a charge
The number of protons is not equal to the number of electrons!
Isotopes are atoms of the same element with different masses (different numbers of neutrons)
Carbon-12
Carbon-13
Carbon-14
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Question For an atom of Magnesium-24 with a
2+ charge, how many:
Protons:
Neutrons:
Electrons:
Answer Magnesium-24 with 2+ charge
Atomic # = 12 (protons)
Mass # = 24 (protons + neutrons)
Protons: 12
Neutrons: 24 – 12 = 12
Electrons: it had 12 but lost 2 so 10
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Question Write the electron configuration for
potassium (K).
How many electrons are in the second energy level?
How many valence electrons?
Answer Potassium K:
1s22s22p63s23p64s1
How many electrons are in the second energy level? 8
How many valence electrons? 1 (look at outer s and p orbitals)
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Question
What does the Aufbau principle state?
Answer Electrons fill orbitals with lowest
energy first
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Question How many valence electrons does
nitrogen have?
Write the electron configuration and circle the valence electrons
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Answer N: 1s22s22p3
5 valence electrons (electrons in the outer s and p orbitals) You can see it in the electron
configuration or you can look at the group number (group 5A = 5 valence electrons)
Question
What type of ion is nitrogen going to form? Explain.
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Answer N: 1s22s22p3
5 valence electrons so it only needs 3 more to have 8 (the octet)
Gains 3
Forms N 3-
Question
Why do ions form?
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Answer Octet rule
Atoms will gain, lose, or share electrons in order to get an octet
8 valence electrons in outer s and p orbitals
Question
What are the rows called? What are the columns called?
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Answer Rows = periods, series
Columns = groups, families
Question Where are the metals, nonmetals,
and metalloids located?
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Answer Metals – to the left of the zig zag line
Nonmetals – to the right of the zig zag line
Metalloids – along the zig zag line
Question Identify the following groups by name:
1:
2:
17:
18:
Groups 3-12:
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Answer Identify the following groups by name:
1: Alkali Metals
2: Alkaline Earth Metals
17: Halogens
18: Noble Gases
Groups 3-12: Transition Metals
Question Which atom has the smallest atomic radius?
Li
Na
K
Rb
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Answer Lithium (Li)
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Question Identify whether it is ionic, metallic, or covalent:
1. Occurs between a metal or nonmetal
2. When two atoms share electrons
3. When electrons move freely from atom to atom
4. When there is a transfer of electrons
5. Substances with this type of bond have a crystal lattice structure/arrangement of atoms
Answer
1. Occurs between a metal or nonmetal - IONIC
2. When two atoms share electrons – COVALENT
3. When electrons move freely from atom to atom – METALLIC
4. When there is a transfer of electrons - IONIC
5. Substances with this type of bond have a crystal lattice structure/arrangement of atoms – IONIC
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Question What is the formula for iron (III)
oxide?
Answer
Fe2O3
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Question What is the name of the compound? MgO
Answer Magnesium oxide