Answer :
Final answer:
Absolute zero is the lowest possible theoretical temperature at which molecular motion stops, defined as 0 Kelvin, -273.15° Celsius, and -459.67° Fahrenheit. It is a critical concept in physics, so option 1 is the correct answer.
Explanation:
Absolute zero is the theoretical temperature at which all molecular motion ceases. This temperature is defined as 0 Kelvin (0 K), which is equivalent to -273.15° Celsius and -459.67° Fahrenheit. The concept of absolute zero arises from studying the properties of gases and their behaviors at different temperatures. Scientists have also linked absolute zero to phenomena such as superconductivity and superfluidity, which occur at temperatures close to absolute zero. It is measured on the Kelvin scale and is 0 K, which is equivalent to -273.15°C and -459.67°F. At absolute zero, all molecular motion ceases.
The Kelvin scale is the temperature scale that uses absolute zero as its null point, making it the basis of the International System of Units (SI) for temperature. On the Kelvin scale, there are no negative numbers, as it starts from this lowest possible point. The other common temperature scales, Celsius and Fahrenheit, have negative values corresponding to temperatures below their respective zero points.