There are several variables that can affect the thermal energy of an object:
Temperature: The higher the temperature of an object, the greater its thermal energy.
Mass: The greater the mass of an object, the greater its thermal energy.
Specific heat capacity: The specific heat capacity of a material determines how much energy is required to raise its temperature. Materials with a higher specific heat capacity require more energy to raise their temperature, resulting in a higher thermal energy.
Phase: The phase of an object (solid, liquid, or gas) can affect its thermal energy. For example, it takes more energy to change the phase of a substance from solid to liquid or from liquid to gas than it does to raise its temperature within a given phase.
Surface area: The greater the surface area of an object, the greater the amount of heat it can absorb or release, leading to a change in thermal energy.
Thermal conductivity: The thermal conductivity of a material determines how quickly it can transfer heat. Materials with high thermal conductivity can transfer heat quickly, resulting in a higher thermal energy.