Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

If I have two elements A and B, is the compound AB the same as BA?

  1. Oct 25, 2012 #1
    Is there a specific reason for how compounds are named? Like NaCl for instance, what's the criteria to have NaCl rather than ClNa?
  2. jcsd
  3. Oct 25, 2012 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    There is a tendency to put the positive ion (or the element that acts as a donor of electrons) first so Na trumps Cl for first place - also why water is H2O and not, say, HOH. As you advance through chemistry you'll find there are lots of equivalent ways of writing out chemical names.
  4. Oct 25, 2012 #3


    User Avatar

    Staff: Mentor

    The only specific reason is that IUPAC defined naming rules so that when we talk about compounds we can name them in a way that is unique and unambiguous.

    Not that all names assigned using IUPAC rules are unique and unambiguous, as the rules evolved with time, so some older publications can use different names than the current ones.
  5. Oct 25, 2012 #4
    yes its the same thing lol. in general elements commute unlike operators in QM.

    this works only for elements though. in polymers and in anisotropic materials order of the constituents matters.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook