There are lots of possible states of matter that depend on a variety of conditions, the most important of which (for everyday life) is temperature. So, usually, heating a solid melts it into a liquid, which then evaporates into a gas. If you heat a gas even more, you can strip the electrons off the atoms to create a plasma. This is what the sun is made of, and you can also find plasmas in lightning, neon lights, and plasma-screen TVs.
There are also weird intermediate states like liquid crystals. And you might have played with corn flour, which flows like a liquid but feels like a solid if you hit it. These states of matter are not so well understood!
In biology, we usually look at molecules that are aqueous, or dissolved in water (like salts in seawater). Sometimes, though, your cells separate out different molecules into 2D liquids (like membranes) or strange semi-solid condensates or even solid crystals!