Change to kelvin: (a) 57 °C, (b) -120 °C. Change to degrees celsius: (c) 520 K.

$\text{K} = {}^\circ\text{C} + 273$ and ${}^\circ\text{C} = \text{K} - 273$. A step of $1\ \text{K}$ is the same size as a step of $1\ ^\circ\text{C}$. A substance is a solid below its melting point, a liquid between its melting and boiling points, and a gas above its boiling point.