Regarding temperatures in kelvins: (a) Convert \(-100.5^{\circ} \mathrm{C}\) to kelvins. (b) What is wrong with someone telling you the temperature of something is \(-100.5 \mathrm{~K} ?\) (c) What is the coldest possible temperature in \({ }^{\circ} \mathrm{C} ?\)

The Kelvin scale is fundamentally important in the field of science, particularly in the study of thermodynamics and physics. Unlike the Celsius and Fahrenheit scales, which are based on the properties of water, the Kelvin scale is based on thermodynamic temperature, with its starting point at absolute zero—the point at which no more thermal energy can be removed from a system.

Units on this scale are called kelvins (K), not degrees Kelvin, and it was named after the Scottish physicist and engineer William Thomson, 1st Baron Kelvin. The scale does not have negative numbers because it starts at absolute zero, where all thermal motion ceases. This property is essential for scientific calculations, as it allows the use of absolute temperature in formulas without having to take into account the different starting points of other temperature scales.

The Kelvin scale is widely used in scientific research, as it allows for the precise measurement of temperatures and easy conversion to other units of temperature via simple arithmetic, improving the clarity and consistency of temperature-related data.

The process of converting Celsius to Kelvin is a straightforward arithmetic task, which relies on understanding the fixed point that links the two scales. The key to this conversion lies in the fact that the size of one degree Celsius is exactly equal to the size of one kelvin. However, their starting points differ; 0°C is equivalent to 273.15 K.

Therefore, to convert a temperature from Celsius to Kelvin, one adds 273.15 to the Celsius temperature. For example, boiling water at sea level, which occurs at 100°C, would be 373.15 K in the Kelvin scale (\(100 + 273.15 = 373.15\text{K}\)).

This simple relationship enables accurate and easy conversions which are vital for scientific work where precise temperature measurements are required. It is essential for students to understand this process as it forms the basis for thermal physics and many real-world applications, such as calculating the energy of particles in a substance.

Absolute zero is a cornerstone concept in thermodynamics and it represents the lowest limit of temperature theoretically possible. At absolute zero, corresponding to 0 K, the particles within a substance have minimal vibrational motion, effectively retaining no thermal energy.

This concept is not just theoretical; it has practical implications in the study of materials at very low temperatures. For instance, phenomena such as superconductivity, where materials conduct electricity without resistance, occur near absolute zero. In reality, reaching absolute zero is physically unachievable, but scientists have come incredibly close in controlled laboratory environments.

Understanding absolute zero is crucial for grasping the laws of thermodynamics, which govern the transfer and transformation of energy. It is a benchmark for temperature scales and serves as a base point from which scientists measure the absolute temperature of objects, allowing them to explore the fundamental properties of matter.