* Identify the known parts:
* Ca: Calcium, an alkaline earth metal (Group 2)
* O: Oxygen, a non-metal (Group 16)
* X: The unknown element
* Consider the charges:
* Calcium (Ca) usually forms a +2 ion (Ca²⁺).
* Oxygen (O) usually forms a -2 ion (O²⁻).
* We need to determine the charge on the unknown element (X) to balance the compound.
* The compound is neutral: The overall charge of the compound must be zero.
Deduction:
Since Ca has a +2 charge, and each oxygen has a -2 charge, the total charge from the Ca and O is already balanced: (+2) + 4(-2) = -6.
To balance the overall charge of the compound to zero, the unknown element (X) must have a +6 charge.
Possible Elements:
* Chromium (Cr): Chromium can form a +6 oxidation state in compounds like chromates (CrO₄²⁻).
Therefore, a possible compound could be CaCrO₄, calcium chromate.
Important Note: There might be other elements that could form a compound with CaXO4 under specific conditions, but chromium is the most likely candidate given the common oxidation states.
