The particles are gaining/losing energy... and therefore move faster or slower... therefore changing state and some physical properties.
Because it cools down and changes its state of mater.
stuff
Penn State Alma Mater was created in 1901.
Mater and Pater. They were regularly used among aspirational middle-class English families well into the Twentieth century.
Solid, liquid, gas, plasma.
Solid
solid state
It is a solid.
solid
it is a solid
liquid
"In the state of celibacy"; unmarried.