How many molecules of phosphoric acid (H3PO4) react with excess calcium carbonate to produce 4 moles of Ca3(PO4)2

I’m not sure what your trying to say here.. can you clarify again?

Ithink is a because if say increased in electronegativity

Sorry i dont understand the question can you rephase it?

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts