Final answer:
Thermal energy is the kinetic energy of the random motion of atoms and molecules, with factors like temperature, mass, and phase affecting how much an object has. Heat refers to the transfer of this energy between objects due to temperature differences.
Step-by-step explanation:
Thermal energy is kinetic energy associated with the random motion of atoms and molecules within an object. The more rapidly these particles move, the higher the object's thermal energy. For instance, when atoms and molecules in an object are moving or vibrating quickly, they have a higher average kinetic energy, and we say the object is "hot." Conversely, when they move more slowly, they have lower kinetic energy, and the object is perceived as "cold."
Factors Determining the Amount of Thermal Energy
The amount of thermal energy an object has can be determined by several factors, including:
The object's temperature: This is a measure of the average kinetic energy of the particles in the object. The higher the temperature, the more thermal energy the object contains.
The mass of the object: A larger mass usually contains more thermal energy because it has more particles that can possess kinetic energy.
The phase of the object (solid, liquid, or gas): Different phases have different levels of particle movement associated with them, which affects the amount of thermal energy.
Whether the object is undergoing any chemical or physical processes, such as endothermic or exothermic reactions, which can absorb or release energy respectively.
It is important to distinguish between thermal energy and heat, as heat refers to the transfer of thermal energy between two objects due to a temperature difference.