When you're waiting for a pot of water to heat up on the stove, tiny bubbles are the first sign it's getting ready to boil. As the water gets hotter, the bubbles get bigger, until a rolling boil ...

Before we can answer that question, we need to know first: What is a solid? What’s a liquid? What’s a gas? These three materials behave in terms of the tiny particles of which they’re made. Solids, ...