Here's how we determine that:
* Ionic Compounds: These compounds are formed by the electrostatic attraction between positively charged ions (cations) and negatively charged ions (anions).
* Balancing Charges: To form a neutral compound, the total positive charge must equal the total negative charge.
* Ca²⁺: Calcium has a +2 charge.
* NO₃⁻: Nitrate has a -1 charge.
* Ratio: To balance the charges, we need two nitrate ions (2 x -1 = -2) for every one calcium ion (+2).
* Formula: This gives us the formula Ca(NO₃)₂.
