[lojban] ratni

[MorphemeAddict@wmconnect.com]

I was looking at the Lojban Wikipedia yesterday, and I noticed some inconsistency in usage of the word "ratni".

How should one say, e.g., "Hydrogen is element number 1"?

The definition of "ratni" is 
x1 is an atom of element/atomic number x2 of isotope number/atomic weight x3

It seems to me that both "hydrogen" and "number one" go in x2.  

Is this right?
le cidro cu ratni li pa
le cidro cu se ratni li pa
le cidro pe li pa cu se ratni

stevo