Linked from
The 48 pages that link to Calcium, each with the reason it gives.
Flame testBroader topic: Its orange-red color can help distinguish calcium from other tested ions.
Calcium chlorideBroader topic: Calcium atoms form the doubly charged cations in calcium chloride.
Calcium fluorideBroader topic: Calcium ions supply the positive charge in calcium fluoride.
Calcium citrateBroader topic: Calcium is the mineral supplied by calcium citrate.
Calcium sulfideBroader topic: Calcium supplies the doubly charged cation in calcium sulfide.
Period 4 elementBroader topic: It follows potassium before the 3d transition series begins.