A lot of energy’s exchanged
When matters’ states are rearranged,
Exciting liquids into gases
Or slowed down to solid masses.
The tricky bit with change of phase
Is on the cusp, ’cause matter stays
The way it is until it can’t,
And that’s why, when I run, then plant
My solid backside in a chair,
I won’t be going anywhere
Until the liquid pressure grows
Too great. (Gas works, too, I suppose.)