No, the specific heat capacity of a substance is not unique to that substance in the same way that the wavelength of an electromagnetic (EM) wave is specific to that particular wave.
The specific heat capacity of a substance refers to the amount of heat energy required to raise the temperature of a unit mass of that substance by a certain amount. It is an intrinsic property of the substance and is typically expressed in units of joules per kilogram per degree Celsius (J/kg°C) or joules per gram per degree Celsius (J/g°C). Different substances have different specific heat capacities because they possess varying degrees of internal energy storage and respond differently to the addition or removal of heat.
On the other hand, the wavelength of an electromagnetic wave is a characteristic property of that wave and is determined by its frequency. In the electromagnetic spectrum, different types of waves (e.g., radio waves, visible light, X-rays) have distinct wavelengths associated with them. The wavelength of an EM wave is independent of the material through which it propagates. It is a fundamental property of the wave itself, unrelated to specific heat capacity or the properties of any particular substance.
In summary, the specific heat capacity of a substance is a material-specific property related to thermal energy storage, while the wavelength of an electromagnetic wave is a characteristic property of the wave itself, independent of the medium through which it travels.