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33 questions
Which of the following observations led Thomson to conclude that cathode ray particles were negatively charged?
He observed that a metal plate exposed to cathode ray particles became positively charged.
He observed that positively charged plates repelled the rays.
He observed that cathode ray particles traveled in a straight path through electric fields.
He observed that negatively charged plates repelled the rays.
An element is identified by its ___
number of protons
number of neutrons
number of electrons
atomic mass
Why is the atomic mass that is listed on the periodic table a decimal number?
the nucleus doesn’t always contain whole protons and neutrons
it is that precise of a measurement
it is an average mass of all of the isotopes for that element
it represents a portion of a gram
Naturally occurring europium (Eu) consists of two isotopes. Europium-151 has an abundance of 48.03%. Europium-153 has an abundance of 51.97%. What is the average atomic mass of europium according to these measurements?
152.04
151.97
151
76.0197
In a vacuum, all electromagnetic waves travel at the speed of light (c = 3.00 x 108). What is the frequency of a light wave that has a wavelength of 6.80 x 10-7 m?
4.41 × 1014 Hz
2.04 s
2.04 × 109 Hz
2.27 × 10-15 Hz
Which of the following correctly depicts the trend in electronegativity?
Identify the period and group numbers of the element with the electron configuration. [Ne]3s23p4
Period 3, Group 16
Period 2, Group 16
Period 3, Group 4
Period 2, Group 4
A scientist filters a sample of river water. The data from this process is shown above. These data support which of the following descriptions of the sample?
It is a mixture because solid particles are separated from the river water.
It is a pure substance because the river water is composed only of free elements.
It is a pure substance because solid particles cannot pass through the filter paper.
It is a mixture because dissolved ions in the water pass through the filter paper.
Which of the following statements describes an element’s physical property?
Liquid helium changes to a gas at -269oC
Hydrogen gas is very flammable
Sodium in water forms sodium hydroxide and hydrogen.
Fluorine atoms gain an electron when they react.
Two solutions were mixed in a test tube at a time.
Solution X is colorless and transparent.
Solution Y is colorless and transparent.
Solution Z is pale blue and transparent.
Notes of the results observed are listed in the table above.
Which of the combinations showed evidence that a chemical change may have taken place? Check all that apply.
Combination 1
Combination 2
Combination 3
all of these are chemical changes.
Which of the following would be considered extensive properties of iron?
density, boiling and melting points
mass only
magnetic attraction and density
all of the properties are extensive
The number of significant digits is 170.040 km is __
3
4
5
6
When dry ice converts from a solid to a gas, this is known as __
condensation
melting
sublimation
deposition
Which Lewis electron dot structure below correctly represents calcium oxide?
Which of the following is NOT TRUE of compounds?
compounds form when two or more elements chemically combine
compounds usually have the same properties of the elements that make them up
the chemical formula tells what elements the compound is made of
All of these are true of compounds.
All of the following are likely to form IONIC bonded compounds EXCEPT:
NH3
RbF
MgCl2
K2S
Name the compound Li3N.
lithium nitrogen
lithium nitride
lithium nitrate
lithium (III) nitride
Name the compound CuCO3. USE YOUR OXIDATION NUMBERS!
copper (III) carbonate
copper (II) carbonate
copper carbonate
copper carbon oxide
Name the compound Fe2O3. Check your oxidation numbers!
iron (II) oxide
iron hydroxide
iron oxide
iron (III) oxide
What is the formula for copper (II) chloride?
Cu2Cl
Cu2Cl2
CuCl
CuCl2
What is the formula for potassium carbonate?
K2(CO3)1
K2CO3
K(CO3)2
KCO3
A chemical bond resulting from the attraction between positive metal and negative nonmetal ions is called
dipole bond.
ionic bond
covalent bond
charged bond
Your lab partner drew the Lewis electron dot structure for CO2 shown above. He asks you if this structure is correct. What should you tell him needs to be changed?
The bonds between carbon and oxygen should be triple bonds.
The shape of the molecule should be bent instead of linear.
The bonding between carbon and oxygen should be ionic.
The central carbon atom should have eight valence electrons.
Which of the following shows the INCORRECT electron diagram?
A molecule of nitrogen gas (N2) has
a single bond
a lone pair
a double bond
a triple bond
An aluminum atom has 3 valence electrons. What is the structure of a molecule of aluminum trichloride (AlCl3) according to VSEPR theory?
trigonal planar
trigonal pyramidal
linear
tetrahedral
Since 1998 car airbags have reduced the number of fatalities in front end collisions by 30%. When the crash sensor detects a front-end collision, sodium azide, NaN3, produces nitrogen gas which quickly inflates a thin nylon bag. The reaction (shown below) is classified as--
2NaN3 (s) --> 2Na (s) + 3N2 (g)
single displacement
synthesis
combustion
decomposition
The diagram shows a balance being used to measure a burning candle in a sealed glass ball before and after the burning is complete. As the candle burns, the size of the candle decreases, but the reading on the balance does not change. Which of the following is demonstrated by this experiment?
total mass is conserved
smoke particles have more mass when than molecules of the candle wax
energy is converted to mass when the candle is burned
kinetic energy is converted to potential energy when the candle is burned
Which of the following single replacement reactions will not occur?
Zn + CaSO4 -->ZnSO4 + Ca
Zn + 2HCl --> ZnCl2 + H2
Cu + 2AgNO3 --> 2Ag + Cu(NO3)2
Mg + 2H2O --> Mg(OH)2 + H2
What is the oxidation number of the iron (Fe) atom in the compound Fe2O3?
+2
-2
+3
-3
Zn(s) + CuCl2(aq) --> ____
The substances above will—
not react because copper and zinc are both dissolved
not react because zinc is less active than copper
react in a double replacement reaction
react in a single replacement reaction
Which product balances the chemical equation below?
3AgNO3 (aq) + FeCl3 --> 3AgCl + _______
FeNO3 (aq)
FeCl2 (aq)
FeCl (aq)
Fe(NO3)3 (aq)
Which of the following is insoluble and will form a precipitate?
Ca(OH)2
CaCO3
KNO3
NaCl
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