SI Unit of Temperature. It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380 649 × 10⁻²³ when expressed in the unit J K⁻¹, which is equal to kg m² s⁻² K⁻¹, where the kilogram, metre and second are defined in terms of h, c … The Celsius and the Kelvin scales have equal-sized units, but 0 o C is equal to 273.15 K. This makes it … Explanation: The kelvin (K) is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380 649 ×10−23 when expressed in the unit J K−1, which is equal to kg m2 s−2 K−1, where the kilogram, meter and second are defined in terms of h, c and ∆νCs. The Kelvin scale was determined based on the Celsius scale, but with a starting point at absolute zero. Kelvin temperature scale is the base unit of thermodynamic temperature measurement in the International System (SI) of measurement. The SI base unit of temperature is the kelvin (K). The kelvin is the base unit of temperature in the International System of Units (SI), having the unit symbol K. It is named after the Belfast-born Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907). Well, the real reason the kelvin is an SI base unit is that when the Kelvin temperature scale was first developed (1848 according to Wikipedia), people didn't realize that temperature was connected to energy, so the kelvin as a unit took on a "life" of its own. It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380 649 x 10 –23 when expressed in the unit J K –1, which is equal to kg m 2 s –2 K –1, where the kilogram, metre and second are defined in … The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. However, in most parts of the world, Celsius or Fahrenheit scale is used for measuring temperature. The kelvin (note the lowercase letter) is the base unit of temperature in the International System of Units (SI). Each unit on this scale, called a Kelvin rather than a degree, is equal to a degree on the Celsius scale. All matter—solid, liquid, and gas—is composed of continuously jiggling atoms or molecules. The SI unit of temperature as per the International System of Units is Kelvin which is represented by the symbol K. The Kelvin scale is widely accepted or used in the field of science and engineering. The kelvin, symbol K, is the SI unit of thermodynamic temperature. A) Kelvin. The kelvin, symbol K, is the SI unit of thermodynamic temperature. Because of this random motion, the atoms and molecules in matter have kinetic energy. Temperatures in the Kelvin scale are 273 degrees less than in the Celsius scale. The kelvin scale is an absolute temperature scale, that is a scale on which the lowest temperature possible is zero.