Here's why:

* Smoke is a colloid: It's a mixture where tiny solid particles are suspended in a gas. Think of it like dust particles floating in the air.

* The solid particles: These come from the incomplete combustion of materials, like wood or fuel. They are mostly carbon particles, but can include other compounds depending on what's burning.

* The gas: This is typically air, but can include gases released during combustion, like carbon dioxide and water vapor.

So, while smoke appears to be a hazy gas, it's actually a complex mixture of tiny solid particles dispersed within a gas.