Thermal Energy Study Guide

A compilation of vocabulary flashcards related to key concepts in thermal energy and heat transfer.

Specific Heat

The heat required to raise the temperature of the unit mass of a given substance by a given amount (usually one degree).

Heat

Thermal energy transferred between objects due to a temperature difference.

Temperature

Average kinetic energy of an object.

Thermal Energy

Total energy of the molecules of a substance.

Thermal Equilibrium

Occurs when heat transfer causes the temperature of two objects to be the same.

Endothermic

Energy is absorbed by the substance.

Exothermic

Energy is released by the substance.

State of Matter

The distinct forms that different phases of matter take on, including solid, liquid, gas, and plasma.

Phase Change

Occurs when thermal energy is released or absorbed, causing a change in the state of matter.

Fahrenheit, Celsius, and Kelvin

The three temperature scales.

Celsius Scale

Based on the freezing (0ºC) and boiling points (100ºC) of water.

Kelvin Scale

Based on absolute zero (0K), the point at which all molecular motion stops.

Conduction

Heat transfer through direct contact, such as walking barefoot on hot sand.

Convection

Heat transfer by the movement of fluids, such as hot air balloon rising.

Radiation

Heat transfer in the form of waves, such as sunlight heating your skin.

Conductor

Materials (like metals) that transmit thermal energy.

Insulator

Materials (like air, cotton, rubber, wood) that prevent the transmission of thermal energy.

Phases of Matter

Plasma, gas, liquid, solid, ordered from highest energy to lowest kinetic energy.

Endothermic and Exothermic Changes of State

Gas to plasma (ionization) is endothermic; plasma to gas (deionization) is exothermic.

Thermal Expansion

The process in which volume increases as temperature rises.

Specific Heat Capacity

Indicates how much energy is required to change the temperature of a substance, such as water having a high specific heat capacity.

Specific Heat of Aluminum

Calculated as Cp = 0.897 J/gºC based on energy absorbed and temperature change.

Heat Absorbed by Water

Calculated using specific heat and temperature change (Q = 48,325.2 J for 330 g of water).

Mass of Water Needed

Calculated to change its temperature by 25°C using 4,532 J of heat energy as m = 43.327 g.

Melting and Boiling Points

Melting point of the substance is -60ºC; boiling point is 60ºC.

Energy Gained by Water

Calculated to be Qwater = 1012.528 J given specific conditions.

Specific Heat of Metal

Calculated as Cp = 0.203 J/gºC based on temperature change.

Percent Error

Calculated as 3.33% error when assuming the metal was tin.

Heat and temp what is the difference

Heat is the transfer of thermal energy and temp is the average kinetic energy

heat flow if the objects are different temps

is the process of thermal energy moving from the hotter object to the cooler object until thermal equilibrium is reached.

what is the 4 phases of matter from highest to lowest energy

plasma, gas, liquid, solid

describe a scenario of a type of heat transfer that results in a phase change was this Endothermic or exothermic

When ice melts to water, heat is absorbed from the surroundings, resulting in an endothermic process.

what does it mean to say a material has a high or low specific heat capacity

It refers to the amount of heat energy required to change the temperature of a unit mass of the material by one degree Celsius. Materials with high specific heat can absorb more heat without a significant change in temperature, while those with low specific heat heat up or cool down quickly.