Don’t lick her or else you’ll have permanently bad breath.

@The Damned  
Well, it’s not like you can spell that in elemental symbols, anyway. Perhaps a synonym, if you have that much animus for her?
 
Bismuth (or Boron, Iodine), Technetium, and Hydrogen may do nicely.

That’s not how you spell cunt

I’d be interested in testing her chemical composition for titanium, carbon, potassium, lithium, sulfur, and hydrogen. A simple tactile test on the abdomen should suffice, lasting for a minute or two, though the human version may warrant additional umbilical and axillary tests. Perhaps these tests will turn up vanadium, erbium, and yttrium first…
 
I mean, I know these elements are present in Applejack, Rainbow Dash, Candy Caramel Tooth, and Flurry Heart already, but I do not wish to simply assume that this is true for all mares and fillies.

@Everypony  
All these comments are cute too.

That pun was also quite CuTe.

According to that, everymare is made of Copper and Tellurium

Also she’s hot. Because  

Nitrogen , Iodine , Cerium

I like it.