Physical Science, Chapter 8, Thermal energy

If ____________________ is transferred from object A to object B, the temperature of object A decreases.

Heat

The movement of thermal energy from a warmer object to a cooler object is called

Heat

A material that prevents the flow of energy is called a(n) ___. A material that permits the flow of energy is called a(n) ____.

Insulator; conductor

The SI unit of heat is the ____________________.

Joule

A one-degree change in temperature on the Celsius temperature scale is equal to a one-unit temperature change on the ____________________ temperature scale.

Kelvin

If two glasses of water are at the same temperature, the average ____________________ energy of the particles of water in each glass is the same.

Kinetic

Heat transfer occurs (what direction?) from ___ to ___.

Only from warmer to colder objects

Energy from the sun is transferred to Earth by the process of ____________________.

Radiation

The transfer of energy by electromagnetic waves is called

Radiation

Iron has a higher specific heat than silver. If 1 kg of iron and 1 kg of silver absorb equal amounts of heat, the temperature of the ____________________ will increase by a greater amount.

Silver

The amount of energy required to raise the temperature of 1 kilogram of a substance by 1 kelvin is called its

Specific heat

A measure of the average kinetic energy of the individual particles in an object is called

Temperature

The more particles an object has at a given temperature,

The more thermal energy it has

An increase in the total energy of the particles in an object results in an increase in the ____________________ energy of the object.

Thermal

Even though the water in a filled bathtub may be at the same temperature as water in a teacup, the water in the bathtub has more ____________________ because it contains a greater number of water molecules.

Thermal energy

Explain the difference between thermal energy and heat thoroughly. (4)

Thermal energy is the total energy of all of the particles of a substace, KE + PE. Heat is the movement of the thermal energy from a substance at a higher temperature to another at a lower temperature.

As the thermal energy of matter increases, its particles usually spread out, causing

Thermal expansion

Joints in train tracks are designed with extra space to allow for __________________ in hot weather.

Thermal expansion

No more energy can be removed from matter at

Absolute zero

Why are double pain windows, containing an air space, more energy efficient than single pain widows? Explain thoroughly. (3)

Air is a poor conductor of heat and thus acts as an insulator. The air space reduces the heat transfer by conduction. Without an air layer, the single pane allows heat to ecape easily by conduction.

Which beakers contain water with the same average kinetic energy per molecule? Explain thoroughly. (4)

Beaker A and B. Temperature is a measure of the average kinetic energy of the particles in a substance. Since the water temperature is the same in both beakers, the water molecules have the same kinetic energy.

Which beaker contains water with the most thermal energy? Explain thoroughly. (4)

Beaker C. The thermal energy of the water increases with temperature and with the number of molecules. Because beaker c has the highest temperature and as much water as any other beaker, it has the most thermal energy.

Heat is transferred from one particle of matter to another without the movement of matter itself in a process called

Conduction

The handle of a spoon in a bowl of hot soup becomes warm due to heat transfer by the process of

Conduction

Describe, in terms of the motion of particles in an object, how heat conduction transfers energy between objects or from one part of an object to another part at a lower temperature. (2)

Conduction transfers energy within an object or between objects when fast moving particles collide with slower moving particles and transfers kinetic energy, making the slower particles move faster. Heat is always transferred from warmer, faster particles of objects, to cooler, slower particles of objects.

Describe how conductors and insulators differ. Include an example of each. (4)

Conductors are materials that permit th flow of energy, such as metals. Insulators are materials that prevent the flow of energy, such as wool.

Which of these is a good conductor? (List 3 conductors & 3 insulators for this question.)

Conductors: metals: copper, iron, silver, gold Insulators: wool, air, paper, rubber

Heated air moves from baseboard heaters to the rest of a room in a process called

Convection