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. 8,912 grams
. 16,382 grams
. 65,534 grams
153,844 grams
Step 4. Shake the bottle.
Observation: The eyedropper will float to the top because water will come out of it, and the volume of air will increase.
Step 4. Squeeze the sides of the bottle.
Observation: The eyedropper will float to the top because water will come out of it, and the volume of air will increase.
Step 4: Shake the bottle.
Observation: The eyedropper will sink to the bottom because water will go inside it, and the volume of air will be reduced.
Step 4: Squeeze the sides of the bottle.
Observation: The eyedropper will sink to the bottom because water will go inside it, and the volume of air will be reduced.
In which state, or states, of matter can particles expand to completely fill their container?
I
II
III
I, II, and III
Robert measured the air pressure in his bicycle tire, and it was low.
What can Robert do to increase the air pressure in his tire?
increase the density of the air
increase the volume of the air
decrease the density of the air
decrease the temperature of the air
I = solid phase
II = liquid phase
III = plasma phase
III = gaseous phase
Leah is cleaning her collection of old pennies using vinegar. As she cleans them, the following chemical reaction occurs:
What action will show that mass is conserved in this chemical reaction?
comparing the types of products and reactants
comparing the weights of the products and the reactants
comparing the physical appearance of the products and the reactants
comparing the number of molecules in the products and the reactants
Which of the following actions will increase the rate at which a sugar cube dissolves in water?
stir the water before adding the sugar
cool the water before adding the sugar cube
cool the sugar cube before adding it to the water
crush the sugar cube before adding to the water
What is the name of the compound CCl4?
carbon chloride
cobalt chloride
carbon tetrachloride
monocobalt tetrachloride
Two students are discussing the law of conservation of mass. The students disagree on how to test conservation of mass, especially when the reaction involves the combustion of charcoal. Student A believes that burning charcoal violates the Law of Conservation of Mass because the charcoal produces heat when it burns, and the ashes weigh as much as the original briquettes. Student B believes that student A is mistaken because some of the products produced when burning charcoal are gases, and it is difficult to capture gaseous products.
Which experiment will provide the BEST method for testing the law of conservation of mass when burning charcoal?
Place a pre-weighed briquette of charcoal into a pre-weighed porcelain dish. Heat the dish to cause the briquette to burn. Allow the charcoal to burn completely to ash. Weigh the ash and the dish. The initial mass of the briquette and the dish should be equal to the final mass of the ash and the dish.
Place a pre-weighed briquette of charcoal into a pre-weighed porcelain dish inside of a combustion chamber containing a known mass of oxygen. Heat the dish to cause the briquette to burn. Allow the charcoal to burn completely to ash. Collect all the combustion gases while the briquette is burning. The total initial mass should equal the total final mass.
Place a pre-weighed briquette of charcoal into a porcelain crucible. Heat the crucible to cause the briquette to burn. Allow the charcoal to burn completely to ash. Collect the combustion gases by bubbling them through water. The mass of the charcoal should equal the mass of the ash plus the mass of heat released, and the mass of gases produced.
Place a pre-weighed piece of charcoal into a porcelain dish. Heat the dish to cause the charcoal to burn completely to ash. Collect the combustion gases after bubbling them through water. The mass of the charcoal and the dish should equal the total mass of products less the mass of heat produced
Chromium-55,
55
Cr
, is a radioactive isotope used in scientific research. It has a half-life of 2 hours. A scientist can perform her experiments as long as the original sample contains AT LEAST 15 grams of non-decayed chromium-55.
If a scientist begins with 1,000 grams of chromium-55 at 06:00, by what time of the day MUST she complete her experiment? (Note that time is given in 24-hour clock format)
14:00
16:00
18:00
20:00
BF3
BFl3
BaF3
BaFl3
Ruth, because there were no air bubbles adhered to the walls of the pot.
Betsy, because there were no air bubbles adhered to the walls of the pot.
Ruth, because there were several air bubbles adhered to the walls of the pot.
Betsy, because there were several air bubbles adhered to the walls of the pot.
Which of the following is the MOST important to know when writing the formula of hydrogen sulfide?
the sign of the charge carried by hydrogen and sulfur ions
the number of electrons lost by sulfur to hydrogen and gained by sulfur
the number of electrons lost by hydrogen to sulfur and gained by hydrogen
the charge carried by the neutral hydrogen atom and the neutral sulfur atom
Suppose you extract one gram of carbon from an ancient wooden hammer handle. You find that your ancient gram of carbon is half as radioactive as a gram of carbon extracted from a tree branch that was cut today. The half-life of C-14 is 5,730 years.
Assuming that today’s ratio of C-14 to C-12 is the same as when the hammer was made, how old would you estimate is the hammer?
1,432.5 years old
2,865 years old
5,730 years old
11,460 years old
Method 1
Method 2
Method 3
Method 4
Ricardo wants to investigate the relationship between temperature, pressure and the volume of gases. He inflates a balloon with helium and thinks of a plan to increase its volume.
Which of the following actions could increase the volume of his balloon?
place the balloon in the refrigerator
release the balloon and let it rise in the air
place the balloon over a pot with boiling water
submerge the balloon to the bottom of a pool
1
2
3
4
Plutonium-238 decays with a half-life of approximately 88 years along the radium series, eventually becoming lead-206. The fraction of a radioisotope that has decayed is given by the following formula:
where t
is the time of decay in years, and t
1
2
is the half-life of the radioisotope in years.
What percentage of the original mass of plutonium-238 is CURRENTLY available to supply electrical power to the Voyager 2?
27.6%
72.4%
22.6%
77.4%
Do both models show that the chemical reaction obeys the Law of Conservation of Mass?
Yes; the balanced chemical equation represented by columns indicating the number of atoms of each element, and the table with equal amounts of mass for the products and the reactants shows that the reaction obeys the Law of Conservation of Mass.
No; the columns representing the number of atoms of each element in the balanced chemical equation shows that the reaction obeys the Law of Conservation of Mass, but the table showing the masses of the reactants and products does not because the mass of the reactants does not equal the mass of the products.
Yes; the table with equal amounts of mass for the reactants and products shows that the reaction obeys the Law of Conservation of Mass, and the model with the columns shows that atoms of the same elements are found in the reactants and in the products.
No; the table with equal amounts of mass for the reactants and products shows that the reaction obeys the Law of Conservation of Mass, but the model with the columns shows that atoms of the same elements are not equal in the reactants and in the products.
How much of the 35g is NOT dissolved?
20g
15g
10g
0g
What would be the correct balanced formula for a compound made from Aluminum and Sulfur based on balance of charges?
AlS
Which energy source listed provides the MOST energy while creating the LEAST amount of environmental pollution and why?
biofuel; because it reduces the amount of waste in a landfill
geothermal; because it can be harnessed anywhere on Earth
nuclear; because it is a sustainable chain reaction
petroleum; because it is a natural substance that is unlimited
Which of the following solutes has the greatest overall increase in solubility as the temperature of the water is increased?
Ba(NO3)2
Ce2(SO4)
Na2HAsO4
Na2SO4
Which of the following formula and chemical name combinations is correctly shown?
N2O2; nitrogen dioxide
N2O5; dinitrogen pentoxide
Ca2P3; dicalcium diphosphide
PCl5; phosphorus tetrachloride
James washed his clothes at the local laundromat. After washing them, he removed the clothes and noticed that the clothes had undissolved washing powder on them.
Which of the following could James do next time to help prevent this from happening and why?
Wash the clothes in colder water, because lowering the temperature of the solvent increases the rate at which solutes dissolve.
Wash the clothes in colder water, because lowering the temperature of the solvent decreases the rate at which solutes dissolve.
Wash the clothes in hotter water, because raising the temperature of the solvent increases the rate at which solutes dissolve.
Wash the clothes in hotter water, because raising the temperature of the solvent decreases the rate at which solutes dissolve.
Which ionic compound is BOTH correctly written and named?
MgO – magnesium oxide
MnO2 - manganese oxide
NO2 - nitrogen oxide
SrBr - strontium bromide
The diagram shows 32 atoms.
16 of the Red are parent isotopes
16 of the Green are daughter isotopes
How many half-lives have occurred?
0
1
2
3
Which of the following refers to substances that do not mix together and look different throughout?
homogeneous mixture
solution
heterogeneous mixture
solubility curve
What is a positive ion called?
anion
cation
isotope
covalent
What is a negative ion called?
anion
cation
covalent
isotope
Why do elements form bonds?
to get a charge
so they can make friends
to become stable by getting a full valence shell
to become stable by increasing their mass
Examples are Carbon (C) and Uranium (U)
elements
mixtures
compounds
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