][<en

I knew I had the story twisted somewhat.  Sodium and potassium have similar
structures, but differ in the number of atomic particles.  They behave
similarly but are different.  Just like you and me and the rest of the BP
mob, I guess!

Cheers

david

PS  In case you wonder where the email name (Xidawei) comes from, it is the
pinyin transcription of my name in Chinese, with all the components run
together.  Too many other people with the name david west out there for me to
use on a web-based email address!