A molecule of ethanol has two carbon atoms, six hydrogen atoms, and one oxygen atom. A ball-and-stick model of a molecule of ethanol is made from the following components:

one red ball
two black balls
six white balls
eight sticks
What do the black balls in the model represent?

The black balls in the model represent the carbon atoms in the molecule of ethanol.

The black balls in the model of a molecule of ethanol represent the two carbon atoms.

The black balls in the model of ethanol represent the carbon atoms. Ethanol consists of two carbon atoms, so two black balls are used to represent them. Each black ball represents one carbon atom in the molecule.