[jamesrcole]

> H2O is probably the most widely known chemical formula ... Ask those same 19 people what dihydrogen monoxide is ... the answer will be "I don't know but it sounds nasty" ... Yes it's true - half of the population is below average intelligence

I'd go further.

It's really easy to think the meaning of "dihydrogen monoxide" is obvious if you already know how to parse terms written in that language. But it's far from obvious.

To understand what "dihydrogen monoxide" means, you have to know that "di" means "two", and that "oxide" refers to oxygen. You also have to realise that "mon" in this context means "one" - note that it's not "mono", because if it was "mono" then it would be "mono-xide". Actually, it's harder than that, because you need to know how you should break down the words into their components - e.g. that "dihydrogen" should be broken down into "di"-"hydrogen" but not "dihy"-"drogen".

If you haven't learnt the language used to spell out chemical formula you don't have a way to understand the details. I'm sure there's plenty of smart, well educated people who don't have this specific knowledge yet know full well that water is two hydrogen atoms and one oxygen atom.

This issue is more a matter of knowledge than intelligence.

[drdaeman]

I don't know about education in US, but I suspect basic chemistry is a part of compulsory education program. Or I'm wrong?

[jamesrcole]

I can't recall about here in Australia - I did Chemistry as an elective in the final 2 years of high-school, but I can't recall if everyone did that kind of thing in chemistry in earlier years or not.

...but you also have to remember that high-school was a long time ago for a lot of people, and facts like what the prefix "di" means is hardly something most people are going to need to keep in their heads, so are likely to fade over time.

[numo16]

When I was in high school (graduated in 2006), we were only required to take chemistry OR biology, but not required to take both. Those in my class who were afraid of math (most of them) took biology, while the rest of us enjoyed our chemistry fun.