Why CO2 isn't written as O2C

The chemistry side

Contributions Sherry9      Sherry9

11.02.2008, 18:57
Member since 02/2008 4 posts

linkSubject: Naming rules
Is there a rule in the order of the elements when naming a molecule? E.g. one always says CO2 and not O2C or H2O instead of OH2. What's the rule?

(PS: How can I subscript the "2" here?)

12.02.2008, 17:44
Member since 01/2008 2 posts

I also had this question recently. So my chemistry teacher said that when you look at the ions, the element that has a positive charge is always mentioned first. So with H2O the hydrogen ion is positively charged and the oxide ion is negatively charged.
so I guess that's true  
ps: with the subscript of the "2" I don't know either ...
Sherry9      Sherry9

12.02.2008, 18:16
Member since 02/2008 4 posts

Thanks for the answer,
but it still doesn't always fit. E.g. with NH3 nitrogen is more electronegative.
Member since 10/2004 232 posts

Hello, so for most of the compounds you get to know in school - especially the ionic ones - this applies. However, there are exceptions. In principle there is no rule, you have to learn everything by heart.

High and subscript, can be done by using the commands in the editor under '' more ''.