has role calcium(2+) A calcium cation that has formula Ca. BHPQYMZQTOCNFJ-UHFFFAOYSA-N CALCIUM ION Ca Ca(2+) Ca2+ Calcium element InChI=1S/Ca/q+2 [Ca++] calcium calcium(2+) calcium(2+) ion calcium(II) cation calcium, doubly charged positive ion monoatomic dication calcium cation divalent metal cation human metabolite