Final answer:
Specific heat is consistent whether expressed in J/kg·K or J/kg·°C because the temperature change in degrees Celsius is directly equivalent to a change in kelvins. Heat transfer calculations use this property, and a perfectly black object typically remains black in appearance as a blackbody emitter.
Step-by-step explanation:
The value of specific heat is the same in units of J/kg·K and J/kg·°C because the temperature change (ΔT) is the same in both kelvins and degrees Celsius. This implies that the heat capacity of a material does not depend on the chosen temperature scale, as kelvin and Celsius are directly related (a change of 1 Kelvin is the same as a change of 1 degree Celsius).
Heat transfer and specific heat calculations use the formula Q = mcΔT, where Q is the heat transfer, m is the mass, c is the specific heat, and ΔT is the change in temperature. Since a temperature change of 1 degree Celsius is equivalent to a change of 1 Kelvin, specific heat values are consistent across these scales. Specific heat is an intensive property, meaning it does not depend on the amount of the substance.
Regarding the appearance of a perfectly black object when its thermal energy is increased by conduction, it generally will remain black in appearance since blackbody objects are ideal absorbers and emitters of radiation, independent of the temperature change. The term "perfectly black" usually refers to an object that is a perfect emitter and absorber of all wavelengths, thus the color won't change with temperature. An actual object's appearance may vary due to physical and chemical changes at higher temperatures, but this is outside the ideal blackbody approximation.