What of the following is an advantage of the thermal properties of plastic?(1 point)
Responses
Plastics are easy to mold into any shape.
Plastics are easy to mold into any shape.
The thermal conductivity of plastic is very high, making it a good material to transmit heat.
The thermal conductivity of plastic is very high, making it a good material to transmit heat.
Plastics are safe to use in microwave ovens.
Plastics are safe to use in microwave ovens.
Heating plastics eliminates the risk of BPA exposure.
The correct answer is: Plastics are safe to use in microwave ovens.
Which phase change is the opposite of boiling?(1 point)
Responses
freezing
freezing
melting
melting
condensation
condensation
evaporation
The correct answer is: condensation
As the pressure of a gas decreases to half its original value, what happens to the volume of the gas if temperature is held constant?(1 point)
Responses
The volume decreases to half of its original value.
The volume decreases to half of its original value.
The volume increases to four times its original value.
The volume increases to four times its original value.
The volume increases to twice its original value.
The volume increases to twice its original value.
The volume decreases to one-fourth of its original value.
The correct answer is: The volume increases to twice its original value.
There are 300 light particles in an airtight container. Which adjustment would increase the speed of the particles?(1 point)
Responses
keeping the temperature constant and increasing the container volume
keeping the temperature constant and increasing the container volume
keeping the volume constant and replacing the light particles with heavy particles
keeping the volume constant and replacing the light particles with heavy particles
keeping the pressure constant and increasing the temperature
keeping the pressure constant and increasing the temperature
keeping the volume constant and cooling the container
The correct answer is: keeping the pressure constant and increasing the temperature.
The relationships among which variable quantities are expressed by the ideal gas law equation?(1 point)
Responses
pressure, volume, temperature, number of moles
pressure, volume, temperature, number of moles
pressure, volume, number of moles, mass
pressure, volume, number of moles, mass
volume, temperature, number of moles, gas constant
volume, temperature, number of moles, gas constant
pressure, volume, temperature, molar mass
The correct answer is: pressure, volume, temperature, number of moles.
Which statement best describes what it means when something is classified as a strong acid?(1 point)
Responses
It is present in large quantities in a solution.
It is present in large quantities in a solution.
It easily dissociates into ions in solution.
It easily dissociates into ions in solution.
It resists dissociating into ions in solution.
It resists dissociating into ions in solution.
It is present in low quantities in a solution.
The correct answer is: It easily dissociates into ions in solution.
Question
Use the periodic table to answer the question.
An illustration shows the periodic table of elements with elements arranged in increasing order of atomic number in 18 columns (groups) and 7 rows (periods). The electronegativity of elements increases from left to right, across a period. The hydrogen on the left is included in group with medium electronegativity. Also, fluorine is shown as element with highest electronegativity.
Based on patterns in the periodic table, which list shows the acids in order from strongest to weakest?
(1 point)
Responses
HCl, PH3, H2S
HCl, PH 3 , H 2 S
H2S, PH3, HCl
H 2 S, PH 3 , HCl
PH3, H2S, HCl
PH 3 , H 2 S, HCl
HCl, H2S, PH3
Based on the patterns in the periodic table, the correct answer is: HCl, H2S, PH3.
What is the pH of a 1×10−4 mol HCl solution?(1 point)
Responses
8
8
6
6
4
4
2
The correct answer is: 4.
A small amount of sodium hydroxide is added to water. When the chemical reaction reaches equilibrium, the pH is 12. Which statement and conclusion about sodium hydroxide is correct?(1 point)
Responses
The negative log of the concentration of OH– ions is 12. Sodium hydroxide is a strong base.
The negative log of the concentration of OH – ions is 12. Sodium hydroxide is a strong base.
The negative log of the concentration of OH– ions is 2. Sodium hydroxide is a strong acid.
The negative log of the concentration of OH – ions is 2. Sodium hydroxide is a strong acid.
The negative log of the concentration of OH– ions is 12. Sodium hydroxide is a strong acid.
The negative log of the concentration of OH – ions is 12. Sodium hydroxide is a strong acid.
The negative log of the concentration of OH– ions is 2. Sodium hydroxide is a strong base.
The correct answer is: The negative log of the concentration of OH– ions is 12. Sodium hydroxide is a strong base.
Ammonia is a weak base. Potassium hydroxide is a strong base. Which statement is correct?(1 point)
Responses
A solution of potassium hydroxide will always have a higher pH than a solution of ammonia.
A solution of potassium hydroxide will always have a higher pH than a solution of ammonia.
A solution of potassium hydroxide will always have a lesser concentration of solute than a solution of ammonia.
A solution of potassium hydroxide will always have a lesser concentration of solute than a solution of ammonia.
A solution of potassium hydroxide will always have greater conductivity than a solution of ammonia.
A solution of potassium hydroxide will always have greater conductivity than a solution of ammonia.
A solution of potassium hydroxide will always have more OH– ions than a solution of ammonia.
The correct answer is: A solution of potassium hydroxide will always have more OH– ions than a solution of ammonia.
Which phrase describes radioactive decay?(1 point)
Responses
the splitting of a large nucleus into smaller nuclei
the splitting of a large nucleus into smaller nuclei
the joining of small nuclei into a larger nucleus
the joining of small nuclei into a larger nucleus
the triggering of one reaction by the products of another
the triggering of one reaction by the products of another
the spontaneous emission of radiation
The correct answer is: the spontaneous emission of radiation.
Which option would be an appropriate model of nuclear fusion?(1 point)
Responses
mashing two marshmallows together
mashing two marshmallows together
putting a puzzle together
putting a puzzle together
sewing one piece of fabric to another
sewing one piece of fabric to another
adding a drop of water to a glass of water
The correct answer is: adding a drop of water to a glass of water.
Which aspect must be taken into consideration when creating a model of radioactive decay?(1 point)
Responses
There must be a predictable and reversible change that occurs.
There must be a predictable and reversible change that occurs.
There must be a way for unstable nuclei to become stable nuclei.
There must be a way for unstable nuclei to become stable nuclei.
There must not be any changes to the element in question.
There must not be any changes to the element in question.
There must not be any particles or energy emitted from the nucleus.