The conversion from joules (J) to kelvins (K) involves the concept of heat capacity (C) and internal energy (U). According to the First Law of Thermodynamics, heat energy (J) added to a system results in an increase in internal energy (J) and a temperature change (K). The specific heat capacity (J/kgK) of a substance determines the amount of heat required to raise its temperature by 1 Kelvin. Thus, knowing the substance’s specific heat capacity and the amount of heat added, the temperature change can be calculated, effectively converting joules to kelvins.