Final answer:
The Kelvin scale is the temperature scale with only positive values and is extensively used in scientific contexts to measure high and low temperatures; it begins at absolute zero and is the official SI unit for temperature.
Step-by-step explanation:
The temperature scale that has only positive values and is used to measure objects with very high and low temperatures is the Kelvin scale, often used in scientific settings. Unlike Celsius and Fahrenheit, which can have negative values because they are relative scales, the Kelvin scale is an absolute temperature scale. This scale starts at 0 K, known as absolute zero, the point at which no more thermal energy can be removed from a system and there is no molecular motion.
The Kelvin scale is the official SI unit for temperature, making it critical for scientific work, especially in fields like physics and engineering. Temperatures on the Kelvin scale are always positive because they are measured from absolute zero, not from an arbitrary reference point like the freezing or boiling point of water. This scale is essential when dealing with extreme temperatures in various scientific processes and studies, making it invaluable for accurate and consistent temperature measurement and conversion.