Final answer:
Thermal energy is influenced primarily by temperature, mass, and the phase of matter, with temperature being a particularly significant factor. Temperature change affects physical quantities such as thermal expansion, while properties like specific heat and thermal conductivity impact materials' functions, including their use in thermometers.
Step-by-step explanation:
Factors that affect thermal energy include temperature, mass, and phase of matter. Among these, temperature significantly influences thermal energy, as thermal energy is the kinetic energy associated with the random motion of atoms and molecules. A higher temperature means the atoms and molecules move more quickly, thus possessing higher average kinetic energy and, consequently, more thermal energy. Mass is another critical factor since thermal energy is extensive, meaning that greater mass at the same temperature will contain more thermal energy.
Temperature and Thermal Expansion
When an object's temperature changes, physical quantities such as thermal expansion are affected. Thermal expansion results from the increase in average kinetic energy of particles, which makes them move apart. Materials expand upon heating and contract when cooled. This behavior is crucial for designing structures and systems, as they need to accommodate these changes without failing.
Specific Heat and Thermal Conductivity
Properties like specific heat and thermal conductivity impact how materials respond to thermal energy. Specific heat is the amount of heat required to change a material's temperature by a certain amount, influencing how that material will behave as a thermometer. Thermal conductivity measures how well a material conducts heat, affecting the speed at which a thermometer responds to temperature changes.