We have a new mission: to save the world's media from embarrassment.

We want to teach the world some basic science, one word or phrase at a time.

Let's start with carbon dioxide. The chemical formula is CO₂. First note that CO₂ is the chemical formula, not the abbreviation (that would be CD, wouldn't it?).

So, it's capital C (the chemical symbol for carbon, an element), capital O (the chemical symbol for oxygen, another element), not a zero, then a subscript 2 to indicate that there are two atoms of oxygen in the molecule. The digit should always be subscript, not on the line and never superscript.

To make this clear, the following are all wrong: CO2, C02 and CO².