Solid, in physics and chemistry, one of the three states of matter. The other two states of matter are gas and liquid. A solid tends to maintain its shape without a container. Some solids are harder than others. True solids are crystalline; that is, the atoms of which they are composed are arranged in definite, three-dimensional patterns. They have definite melting temperatures. Some substances, such as glass and tar, that appear to be solid are amorphous—they do not have a crystalline atomic structure. These substances soften and melt over a range of temperatures; they are not true solids.
It's lunchtime, and you've spastically spilled soda all over your desk. Chances are you could tackle that mess faster than we could say "Mr. Clean." What do you do though when the spill is radioactive?
Is there a magic equation to the universe? Probably not. But thanks to one man's obsession with rabbits, we have a sequence of numbers that reflect various patterns found in nature.