Scientists use special tools to see how molecules move and arrange themselves. Here's how that helps them figure out the state of matter: * Solid: If the scientist sees the molecules packed tightly together in a regular pattern, and they're mostly just vibrating in place, they're probably looking at a solid. Think of ice! * Liquid: If the molecules are still close together, but they're moving around and sliding past each other, it's likely a liquid. Like water! * Gas: If the molecules are spread far apart and moving around very quickly in all directions, it's probably a gas. Like the air we breathe, or steam.So, depending on how the molecules are behaving, the scientist can tell if they're looking at a solid, liquid, or gas.Hope it help! Pa brainliest po!