Write a chemical formula for each molecular model. (Blue ball represents nitrogen atom, red ball represents oxygen atom, white ball represents hydrogen atom, black ball represents carbon atom, yellow ball represents sulphur atom.)

See answer below

Explanation:

In this case, you are missing the picture. Luckily I found one on another site, so I hope is the one you are asking for. If not, please post again with the picture.

According to the picture below, you need to write a chemical formula for each molecular model.

To do this, is just simple. Let's see each model per separate.

In the first model, we have a blue ball and three white balls. According to the nomenclature of the question a blue ball represents nitrogen atoms and white ball represents hydrogen, therefore, we have an atom of nitrogen bonded to three atoms of hydrogens, so, the chemical formula should be:

NH₃: This molecule corresponds to the Ammonia molecule.

The second picture, shows 4 black balls (representing an atom of carbon each) and each black ball holds a determinated number of white balls. The two of the middle have two white balls each, and the terminals have 3 white balls, therefore, the molecule should be the following:

CH₃ - CH₂ - CH₂ - CH₃: this corresponds to the butane

Finally, the last picture shows a yellow ball (which represents sulphur) and three red balls (representing oxygen each), so, the molecule that represents this would be:

SO₃: this is the sulfite ion.