Question

Is propane, c3h8, an element, a compound, a homogeneous mixture, or a heterogeneous mixture?

Answer 1

Pure substances that cannot be broken down into other substances by any chemical or physical means are known as element.

Pure substances that can be broken down into elements by any chemical or physical means are known as compounds.

Combination of pure substances in which they retain their properties is known as mixture.  

Mixtures in which the components of mixture are uniformly distributed are known as homogeneous mixture whereas mixtures in which its components are can be easily seen are known as heterogeneous mixture.

Since propane, $C_3H_8$ is made up of two different elements that is carbon, $C$ and hydrogen, $H$. There are 3 carbon and 8 hydrogen atoms present in the propane molecule.

So, it is a compound.