Science Chapter 9C

How much thermal energy must be lost by a gram of water at zero degrees C to freeze a gram of ice? What is the quantity of the heat called?

333 J to freeze 1 g of ice at 0 degrees celsius. 333 J/g is taken from the surrounding to freeze.

Describe three ways thermal energy can be transferred. Identify the most effective medium for each method of heat transfer.

Conduction-When a warmer object contacts a cooler one, it transfers kinectic energy to equilibrium. The best medium is diamonds or metal. Covection-thermal energy is transferred from location to another by fluid-the movement of atoms. Forced convection is more efficient. Radiation-It is converted to electromagnetic energy and back to thermal energy at its destination. Dark colors absorb more radiant energy than light colors.

How much thermal energy must a gram of water at 100 degrees C gain to vaporize to a gram of steam at 100 degrees C. What is this quantity of heat called?

Each gram of liquid requires 2256 J of thermal energy to vaporize at 100 degrees C. It is called the Latent heat of Vaporization.

Radiation

Energy that is radiated or transmitted in the form of rays or waves or particles.

State two ways that the arrangement of atoms and the bonding between atoms of a material can influence its insulating abilities.

Gas is a good insulator because their particles are so far apart that they don't transfer thermal energy well. Insulated glass is filled with a glass that prevents thermal energy flow. vacuums are the best insulator. There are no particles present. Thermal energy can only move through a vacuum through radiation. Vacuums are used to insulate thermoses.

Compare and contrast heat capacity and specific heat capacity.

Heat capacity is the thermal energy, in joules, that an object must gain or lose to cause a temperature change of 1 degree C. Specific heat is the heat capacity per gram of material, the amount of material that must be gained or lost to change the temperature 1 gram of the substance 1 degree C.

latent heat of vaporization

The amount of energy required to change a unit mass of a substance from liquid to gas-to boil or condense a mass

latent heat of fusion

The amount of energy required to change a unit mass of a substance from solid to liquid-to melt or freeze

Conduction

The direct transfer of heat from one substance to another substance that it is touching.

heat

The energy transferred between objects that are at different temperatures

Convection

The transfer of heat from 1 location to another by the movement of a fluid

heat capacity

Thermal energy in joules. the number of heat units needed to raise the temperature of a body by one degree.

Discuss the difference between thermal energy and heat.

Thermal energy- is the average sum of kinetic energies of all its particles in an object. Directly proportional to the temperature of the object. Heat -is the quantity of thermal energy that flows from one system to another resulting in a change of temperature or state.

(True or False) Thermal energy added to melting ice at zero degrees C works to break the water molecules out of the ice crystal lattice.

True

How does liquid waters specific heat effect the weather pattern of the world?

Water has a high specific heat capacity. It allows large bodies of water to affect weather.

specific heat

the amount of thermal energy that must be gained or lost to change the temperature of 1 g of substance 1 degree C.