Question

Which of the following is not a correct formula unit for a salt made from main group elements?

Ca0
AIFA
Al2O3
Ca3N2​

Answer 1

The correct option is AlFA

Step-by-step explanation:

There is no element in the periodic table with the symbol of A. Thus, the compound AlFA is wrong and cannot be a salt made from main group elements. CaO is calcium oxide, Al₂O₃ is aluminium oxide and Ca₃N₂ is calcium nitride - all are evidently made from elements from the main groups of the periodic table (except the AlFA)