NLN PAX Science Practice Exam 2026 – Your All-in-One Guide to Exam Success!

Absolute zero is defined as zero on an absolute temperature scale. The Kelvin scale is built so that 0 K represents the lowest possible thermal energy, the point where motion due to temperature would be minimal. Since conversion between scales is K = C + 273.15, 0°C equals 273.15 K, not zero. A value like 273 K is about 0°C, and -273 K would imply a temperature below absolute zero, which isn’t physically meaningful on this scale. So the temperature that reads absolute zero as zero is 0 K.