phy ch 4
Rank the following objects according to their radiant energy, with the most radiant on the top of the list.
1. sun 2. active fire 3. dog 4. ice cube
Why does the aluminum cube need more energy to reach the desired temperature change (to 100°C) compared to the copper cube?
Aluminum and copper are different in their nature. Reason: Because their natures are different, they need different amounts of heat to go through the same temperature change.
______ forces between molecules are termed cohesion and adhesion, depending on whether the force is between like or unlike molecules, respectively.
Attractive
How do humans judge temperature without the use of instruments such as thermometers? Choose the most common process.
By sensing the flow of energy either into or away from their bodies
The laws of thermodynamics are concerned with relationships between which of the following items? (Choose all that apply.)
Heat Work Mechanical energy
Which of the following is true regarding the latent heat of fusion during melting?
It is used to break molecular bonds.
True or false: The primary difference between the Fahrenheit and Celsius temperature scales is the number of degrees that divide the freezing and boiling of water.
True Reason: The Fahrenheit scale has 180 degrees, and the Celsius scale has 100 degrees.
Radiation is a type of heat energy transfer that occurs between two objects ______.
as long as there is a temperature difference between the two
Temperature is based on the ______ molecular kinetic energy of a body.
average
The transfer of energy from one molecule to another is called ______.
conduction
_____ is the transfer of heat due to the movement of molecules.
conduction
Energy ______ occurs when high-quality energy is transformed to low-quality energy.
degradation Reason: This transformation is a natural process.
This is a thermodynamic measure of disorder.
entropy
The heat involved in a solid-liquid phase change, that is, melting or freezing, is called the latent heat of
fusion
The molecules in a ______ are held together with weak forces that allow them to move constantly and randomly.
gas
The phase of matter that has neither a definite volume nor a definite shape is a(n)
gas
The measure of the internal energy that has been absorbed or transferred from one object to another is
heat
To determine how much _____ is needed to change the state of an object, for example, from a solid to a liquid, you need to know the starting temperature of the solid, the mass of the solid, and the nature of the solid.
heat
A device that converts heat into mechanical energy is called a ______.
heat engine
The second law of thermodynamics states that ______.
heat naturally moves from warmer areas to cooler areas
The degradation of energy ______.
is irreversible
The _____ molecular theory is a summary of the scientific assumptions about molecules and the space around them.
kinetic
It gets warmer when it rains because the phase transition of water vapor to rain releases heat. This type of heat is known as ______ heat.
latent
The quantity of heat associated with a phase change is called _____ heat.
latent
Low-quality energy has less order and coherence than high-quality energy, so it is _____ able to do work.
less
The molecules in a ______ flow over each other, yet are held together with relatively strong forces.
liquid
Compared to low-quality energy, high-quality energy is ______ to do work.
more able
A(n) _____ _____ occurs when a solid, liquid, or gas transitions from one phase to another.
phase change
Examples of a ______ include the transition of a liquid to a gas or a solid to a liquid. (Choose the most specific answer.)
phase change
The type of energy transfer you feel as the Sun warms your face on a summer day is due to ______.
radiation
Humans usually judge temperature with their senses in a ______ manner. Assume no instruments are used.
relative
The air above a liquid is _____ when the evaporation and condensation rates are equal.
saturated
The molecules in a ______ are at regular distances from each other and are bound by relatively strong cohesive forces.
solid
Liquids change to gases at relatively low temperatures because ______.
some of the liquid's molecules have high enough energy to escape into the surrounding atmosphere
_____ heat refers to the amount of heat needed to raise the temperature of 1 gram of any substance by 1 degree Celsius. Listen to the complete question
specific
Match the phase change with its proper name.
sublimation-solid to a gas or vapor melting-solid to a liquid condensation-gas or vapor to a liquid freezing-liquid to a solid boiling-liquid to a gas or vapor
The measure of the average kinetic energy of the molecules of a substance is called
temperature
When you refer to how hot or cold an object is, you are describing its
temperature
While the word temperature is commonly used to describe how hot or cold something is, in terms of the kinetic molecular theory, temperature is ______.
the measure of the average kinetic energy of the molecules in a substance
Heat is a measurement of ______.
the total internal energy of the molecules of an object
A perpetual motion machine violates the first and second laws of
thermodynamics
This is the study of heat and its relationship to mechanical energy.
thermodynamics
Conduction is a transfer of energy that occurs ______.
through the interaction of molecules
How is molecular motion increased? (Choose all that apply.)
Absorbing energy Adding heat through a temperature difference
What is the basic premise of the kinetic molecular theory?
All matter is made of atoms.
What is the name of the energy transfer process that is responsible for a typical room having warmer air near the ceiling and cooler air near the floor?
Convection Reason: Convection occurs in fluids, that is, liquids and gases.
What process is occurring if more molecules are escaping the liquid state than are returning to the liquid state?
Evaporation
Which of the following best describes the relationship between the external and internal energy of an object?
External energy is the total potential and kinetic energy of the object; internal energy is the total potential and kinetic energy of the object's molecules.
Which of the following words or phrases correctly describe entropy? (Choose all that apply.)
Lacking a pattern Randomization Disorder Entropy is incoherent, that is, it involves chaotic motion of particles.
What phase of matter has a definite volume but not a definite shape?
Liquid
The phase of matter that has a definite shape and volume is a(n)
Solids have definite shapes and volumes because they have molecules that are nearly fixed distances apart and bound by relatively strong cohesive forces.
What are the three primary qualities that affect how much heat is needed to change the physical state of an object?
Starting temperature of the object Mass of the object Nature of the object
A heat engine uses the heat flow between hot and cold regions to do mechanical work. A heat pump uses work to reverse the natural flow of heat. What prevents you from simply hooking the two together to create a machine that runs itself?
The heat engine cannot convert all the heat into mechanical work.
In a heat pump, unlike a heat engine, ______.
The heat pump does work (W) in compressing vapors and moving heat from a region of lower temperature (QL) to a region of higher temperature (QH). work is used to cool a low-temperature region and heat a higher-temperature region
With molecules continuously moving between the liquid and gaseous states in both directions, what is the primary factor that determines whether evaporation or condensation is occurring?
The number of molecules either leaving or entering the liquid Reason: In evaporation, more molecules are leaving the liquid. In condensation, more molecules are returning to the liquid state.
Given two solid objects of the same initial temperature and mass, why would one melt at a different temperature than the other?
They are made of different materials that have different specific heats. Reason: The nature of the object is the third important factor.
True or false: All objects that you currently can see are emitting radiant energy.
True Reason: It is safe to assume that there are no objects within sight that have a temperature below absolute zero.
True or false: The specific heat of an object affects how readily it heats and/or cools.
True Reason: Specific heat is the amount of heat needed to increase the temperature of 1 gram of a substance by 1 degree Celsius.
The amount of heat required to raise the temperature of a substance is proportional to ______. (Select all that apply.)
the mass of the sample the specific heat of the substance the temperature change
In both the Celsius and Kelvin temperature scales, there exists 100 intervals between the freezing and boiling of water, while in the _____ scale, there are 180 degrees between these two points.
Fahrenheit
True or false: Heat can be completely converted into mechanical energy.
False Reason: A statement of the second law of thermodynamics is that heat cannot be completely converted into mechanical energy.
True or false: The phase change between a liquid and a solid occurs at different temperatures dependent upon the direction of the phase change; for example, the temperature of water freezing is different from the temperature of ice melting.
False Reason: The direction of the phase change does not affect the temperature at which it occurs.
What happens to molecular motion if an object either absorbs energy or heat?
Molecular motion increases.
_____ is the name we use to describe the phase of matter that is a type of gas made of positive ions and negative electrons and is often found in very high temperature conditions.
Plasma
Which of the following equations correctly relates the heat required to change the temperature of a sample of mass m and specific heat c?
Q = mcΔT
What is the correct description of energy flow for saturated air above a body of water?
There is no net energy flow.
Which of the following correctly describes the Fahrenheit and Celsius temperature scales? (Choose all that apply.)
They both are arbitrarily assigned. The numbers used are relative measures of temperature change. Neither is more accurate than the other.
The calorie is a measurement of heat commonly used by nutritionists, whereas the Btu, or _____ _____ _____, is used when describing appliances or energy consumption.
british thermal unit
Match the types of motion that particles of an object have with the correct descriptions.
coherent motion- particles moving together; associated with work incoherent motion- chaotic motion of particles; associated with heating
When considering the interaction of molecules, _____ is the attractive force between the same kind of molecules, whereas _____ is the attractive force between different kinds of molecules.
cohesion; adhesion
Plasmas are like gases but can also ______. (Choose all that apply.)
conduct electricity and interact strongly with magnetic fields.
Oxygen (O2) is an example of a(n) ______, whereas water (H2O) is an example of a(n) ______. Both are composed of atoms, and both can be considered molecules.
element; compound
The first law of thermodynamics commonly is described as an application of the law of conservation of energy, which states ______.
energy can be neither created nor destroyed, just transformed from one form to another
A heat _____ converts heat into mechanical energy.
engine
The first law of thermodynamics can be summarized as follows: The heat energy supplied to a system, minus the work done by the system, is ______ the change in internal energy.
equal to
A liquid may turn to a gas at any temperature through the process of _____, although it does occur more readily with an increase in the liquid's temperature.
evaporation
The external energy of an object is associated with a coherent motion of its particles, while the internal energy of the same object, which is chaotic, is referred to as _____ motion.
incoherent
Traditional thermometers are based upon the idea that substances expand or contract at set rates due to changes in temperature, whereas modern thermometers measure the intensity of the _____ radiation emitted from objects such as the human body.
infrared
While the external energy of an object considers the total potential and kinetic energy that is easily observed, the _____ energy of an object occurs on the molecular level.
internal
