All matter is made up of tiny particles called atoms. There are about 90 different "kinds" of atoms found in nature. Some of these "kinds" of atoms ("elements") are familiar: oxygen, carbon, iodine, helium, mercury, lead, gold, platinum, silver, copper, etc. All atoms of a particular element have one thing in common: the number of positively-charged particles in their midsections - in their "nuclei." So all oxygen atoms have 8 positively-charged particles ("protons"), all helium atoms have 2 protons, all uranium atoms have 88 protons.

Each element has its own set of particular characteristics, like melting point. Boiling point. How much energy it takes to change it from a liquid to a gas. How many bonds - connections with other atoms - it will tend to form. (For a not-showable-in-class dramatization of bonding, see http://www.youtube.com/watch?v=wBCmt_pJTRA )

Carbon likes* to make four bonds. Oxygen likes* to make two bonds. When carbon and oxygen get together with plenty of oxygen around, each carbon atom will join with - "bond with" - two other oxygen atoms.

One carbon atom. With two oxygen atoms. It's called "carbon dioxide" because it has one carbon atom and two oxygen atoms. All carbon dioxide combinations - "molecules" - have just one carbon atom and two oxygen atoms.

Period. End of story. It doesn't make any sense to me that a government official who is trying to influence climate-change policy doesn't understand this.

Well, almost the end of the story.

Remember how all atoms of an element have the same number of protons in their nuclei? There's another big particle found in the nuclei called the "neutron" - called that because it doesn't have any electrical charge - not positive, not negative, but neutral. (Which means that this subatomic particle wasn't found until about 40 years after the first subatomic particle.)

An element can have atoms with different numbers of neutrons even though all of the atoms have the same number of protons. For example, oxygen always has 8 protons in its nucleus. Always, every time; if it's not 8 protons it ain't oxygen. But those neutral particles, those neutrons . . . oxygen can have 8 of them (O-16). Or it can have 10 (O-18). Or 9 (O-17). Each different type of oxygen is called an isotope, and it's the existence of those isotopes that make some of the numbers on the periodic table look really complex. A typical 11th-grade chemistry problem is to figure out the average atomic-level mass given the relative abundance of these isotopes. That average atomic mass is the decimal-heavy number at each element's spot on the periodic table.

Still, CO₂ is CO₂, whether it's from tailpipes or smokestacks or your breath or in the bubbles in your glass of beer.

Where it gets kinda interesting is that if Rosen knew his stuff, he'd understand that the presence of the O-18 and O-16 isotopes helps paleoclimatologists - scientists who study ancient climates - do their job. (Go here for a well-written lay-level description of why this works.) They use long cores of ice drilled from glaciers to figure out how much O-18 was present in the ancient atmosphere compared to the amount of O-16.

Oxygen isotope analysis and CO₂ analysis of ice cores are used along with records found in coral, cave rocks, and tree rings, to provide multiple lines of evidence showing that (a) global warming is now occurring rapidly compared to previous warmings, (b) CO₂ has been a contributing factor to past global warmings and (c) our atmosphere has more CO₂ present now than at any other time during the past 750,000 years.

If Rosen had paid attention in chemistry instead of regarding it as just another potential drag on his GPA, he could ask intelligent questions instead of stupid ones.

*We all understand anthropomorphizing, right?

Image from The Stern Storm

HT:PA