Chapter 4: Heat and Temperature

Flashcard maker : Lily Taylor
The _____ molecular theory is a summary of the scientific assumptions about molecules and the space around them.
Basic unit of matter.
Simple, pure substance made of atoms.
Complex, pure substance made of atoms.
Smallest, ultimate particle of matter that can exist.
What phase of matter has a definite shape and volume?
______ is the attractive force between the same kind of molecules, while _______ is the attractive force between different kinds of molecules.
cohesion; adhesion
The molecules in a ______ flow over each other, yet are held together with relatively strong forces.
The measure of the average kinetic energy of the molecules of a substance is called _____
What phase of matter has neither a definite volume nor definite shape?
Plasmas are like gases but can also ____
conduct electricity; interact strongly with magnetic fields
With an increase in temperature, molecules in a substance move ____
Metals expand or contract in response to change.
glass bulb
A liquid expands in response to the highest reading.
modern medical
Measures infrared radiation emitted from the body.
In both the Celsius and Kelvin temperature scales, there exist 100 intervals between the freezing and boiling water, while in the _____ scale, there are 180 degrees between these two points.
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.
Traditional thermometers are based upon the idea that substances expand or contract at set rates due to changes in temperature, while modern thermometers measure the intensity of the _____ edited from objects such as the human body.
infrared radiation
The boiling of water occurs at 100 degrees C, 212 degrees F, and ____ degrees K.
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.
Heat is a measurement of _____
the total internal energy of the molecules of an object.
The internal energy of an object _____ during heating and ______ during coming.
increases; decreases
______ occurs in two general ways; when energy moves from a region of higher temperature, and through energy-form conversions.
The Calorie is a measurement of heat commonly used by nutritionists, which the Btu, or ______ _______ _____, is used when describing appliances or energy consumption.
British thermal unit
_______ heat refers to the amount of heat needed to raise the temperature of 1 gram of any substance by 1 degree Celsius.
A very rich person heats up 1/4 kg of water in a gold tea kettle with a mass of 1/4 kg until both are at 95 degrees C. The specific heat of water is 33 times that of gold. If both started at room temperature, then _______ absorbed more heat Q, ______ as much as the other object.
33 times; the water
The transfer of energy from one molecule to another is called _______
What is the transfer of heat due to the movement of molecules?
Radiation is a type of heat energy transfer that occurs between two objects______
as long as there is a temperature difference between the two
A ____ _____ occurs when a solid, liquid, or gas transitions from one phase to another.
phase change
The quantity of heat associated with a phase change is called ______ heat.
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.
The heat involved in a liquid-gas phase change, that is boiling or condensation, is called the latent heat of ______
What is true regarding the latent heat of vaporization during condensation?
It originates form the condensing gas.
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.
The same amount of heat energy is supplied to a kilogram of water and a kilogram of aluminum. The specific heat of aluminum is about 1/5 the specific heat of water. If the water increases in temperature by 10 degrees C, you can expect that the aluminum will increase by _____.
50 degrees C
solid to a gas or vapor
solid to a liquid
gas or vapor to a liquid
liquid to a solid
liquid to a gas or vapor
What is true regarding the latent heat of fusion during melting?
It is used to break molecular bonds.
What are the three ways to increase the rate of evaporation?
increase the surface area of the liquid; remove the water vapor near the liquids surface; increase the temperature of the liquid
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.
The air above a liquid is _______ when the evaporation and condensation rates are equal.
A device that converts heat into mechanical energy is called a ____
heat engine
What is the study of heat and its relationship to mechanical energy?
What does a heat engine do?
It converts heat to mechanical energy.
If energy is conserved, how is it possible to change the state of a thermodynamic system by allowing heat to flow in or out, or work to be done on or by the system?
Energy is only conserved if you consider the system plus all its surroundings.
What is a thermodynamic measure of disorder?
coherent motion
Particles moving together; associated with work.
incoherent motion
Chaotic motion of particles; associated with heating
The second law of thermodynamics states that ______
heat naturally moves from warmer areas to cooler areas.
What are the three primary qualities that affect how much heat is needed to change the physical state of an object?
the mass of the object; the nature of the object; the starting temperature of the object
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
heat engine
It can generate mechanical energy from the flow of heat from a hot area to a cold one.
heat pump
It must use mechanical energy to move heat from a cold area to a hot one.
The degradation of energy______
is irreversible
Using the Kelvin temperature scale, the lowest temperature possible is called ____ zero. This is the point at which molecular motion ceases.
What conditions would describe the “heat death” of the universe, a long-term consequence of the second law of thermodynamics?
matter would be arranged randomly; the whole universe would be about the same temperature; matter would be more or less evenly spread out
Coal is burned, creating heat that turns turbines to generate electricity. This electricity is used to run an air conditioner to cool the electrical plant. How is energy degraded or entropy increased?
the air conditioner produces waste heat; mechanical, chemical, and electrical energy is lost to waste heat while mining the coal; the coal is powdered and atoms and ash scattered; not all the heat energy is converted by turbines
A _______ molecule is one composed of two atoms, while a _______ molecule is composed of one atom.
diatomic; monatomic
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.
What is true about a heat pump?
heat pumps convert work into heat; a refrigerator is an example of a heat pump
The first law of thermodynamics can be summarized as follows: The heat energy supplies to a system, minus the work done by the system, is ______ the change in internal energy.
equal to
Materials such as wool and plastic foam that make good heat insulators do so because they have many air pockets that are _____
poor conductors of energy
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.
Compared to low-quality energy, high quality energy is _____ to do work.
more able
Energy ____ occurs when high-quality energy is transformed to low-quality energy.
What is a vapor?
A vapor is the gas form of a substance that is usually found in the liquid phase.

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