Ionic Formulas Worksheet for learning how to write neutral ionic compounds using cations and anions.

You're working on an Ionic Formulas Worksheet that teaches how to write neutral ionic compounds by balancing the charges of cations (positive ions) and anions (negative ions).

The worksheet uses generic symbols:
- A⁺, A²⁺, A³⁺, A⁴⁺ for cations (Ag⁺, Cd²⁺, Cr³⁺, Pb⁴⁺)
- X⁻, X²⁻, X³⁻ for anions (Cl⁻, CO₃²⁻, PO₄³⁻)

The goal is to find the simplest whole-number ratio of ions that makes the total positive charge = total negative charge → resulting in a neutral compound.

---

## ✔ Step-by-Step Solution

We’ll fill in the table row by row, first with generic formulas (A and X), then with actual chemical formulas.

---

🟦 Row 1: Ag⁺ (A⁺) with Cl⁻ (X⁻), CO₃²⁻ (X²⁻), PO₄³⁻ (X³⁻)

#### 1. Ag⁺ + Cl⁻ → AX (already given)
- Charge: +1 + (-1) = 0 → Neutral
- Formula: AgCl

#### 2. Ag⁺ + CO₃²⁻ → ?
- Need 2 Ag⁺ to balance 1 CO₃²⁻ → (2 × +1) + (-2) = 0
- Generic: A₂X
- Actual: Ag₂CO₃

#### 3. Ag⁺ + PO₄³⁻ → ?
- Need 3 Ag⁺ to balance 1 PO₄³⁻ → (3 × +1) + (-3) = 0
- Generic: A₃X
- Actual: Ag₃PO₄

---

🟦 Row 2: Cd²⁺ (A²⁺) with Cl⁻ (X⁻), CO₃²⁻ (X²⁻), PO₄³⁻ (X³⁻)

#### 1. Cd²⁺ + Cl⁻ → AX₂ (given)
- Need 2 Cl⁻ to balance 1 Cd²⁺ → (+2) + 2×(-1) = 0
- Actual: CdCl₂

#### 2. Cd²⁺ + CO₃²⁻ → ?
- Charges: +2 and -2 → 1:1 ratio
- Generic: AX
- Actual: CdCO₃

#### 3. Cd²⁺ + PO₄³⁻ → ?
- Find LCM of 2 and 3 → 6
- So: 3 Cd²⁺ = +6, 2 PO₄³⁻ = -6
- Generic: A₃X₂
- Actual: Cd₃(PO₄)₂ ← *Note: polyatomic ion in parentheses!*

---

🟦 Row 3: Cr³⁺ (A³⁺) with Cl⁻ (X⁻), CO₃²⁻ (X²⁻), PO₄³⁻ (X³⁻)

#### 1. Cr³⁺ + Cl⁻ → ?
- Need 3 Cl⁻ to balance 1 Cr³⁺ → (+3) + 3×(-1) = 0
- Generic: AX₃
- Actual: CrCl₃

#### 2. Cr³⁺ + CO₃²⁻ → ?
- LCM of 3 and 2 → 6
- So: 2 Cr³⁺ = +6, 3 CO₃²⁻ = -6
- Generic: A₂X₃
- Actual: Cr₂(CO₃)₃

#### 3. Cr³⁺ + PO₄³⁻ → ?
- Charges: +3 and -3 → 1:1 ratio
- Generic: AX
- Actual: CrPO₄

---

🟦 Row 4: Pb⁴⁺ (A⁴⁺) with Cl⁻ (X⁻), CO₃²⁻ (X²⁻), PO₄³⁻ (X³⁻)

#### 1. Pb⁴⁺ + Cl⁻ → ?
- Need 4 Cl⁻ to balance 1 Pb⁴⁺ → (+4) + 4×(-1) = 0
- Generic: AX₄
- Actual: PbCl₄

#### 2. Pb⁴⁺ + CO₃²⁻ → ?
- LCM of 4 and 2 → 4
- So: 1 Pb⁴⁺ = +4, 2 CO₃²⁻ = -4
- Generic: AX₂
- Actual: Pb(CO₃)₂

#### 3. Pb⁴⁺ + PO₄³⁻ → ?
- LCM of 4 and 3 → 12
- So: 3 Pb⁴⁺ = +12, 4 PO₄³⁻ = -12
- Generic: A₃X₄
- Actual: Pb₃(PO₄)₄

---

## ✔ Final Completed Table:

| Cation / Anion | Cl⁻ (X⁻) | CO₃²⁻ (X²⁻) | PO₄³⁻ (X³⁻) |
|----------------|------------------|-------------------|---------------------|
| Ag⁺ (A⁺) | AX → AgCl | A₂X → Ag₂CO₃ | A₃X → Ag₃PO₄ |
| Cd²⁺ (A²⁺) | AX₂ → CdCl₂ | AX → CdCO₃ | A₃X₂ → Cd₃(PO₄)₂ |
| Cr³⁺ (A³⁺) | AX₃ → CrCl₃ | A₂X₃ → Cr₂(CO₃)₃ | AX → CrPO₄ |
| Pb⁴⁺ (A⁴⁺) | AX₄ → PbCl₄ | AX₂ → Pb(CO₃)₂ | A₃X₄ → Pb₃(PO₄)₄ |

---

## 🔑 Key Rules Recap:

1. Total positive charge = Total negative charge → Compound is neutral.
2. Use lowest whole number ratio of ions.
3. Polyatomic ions go in parentheses if more than one is needed (e.g., (PO₄)₂).
4. Subscripts are written after the ion symbol — no need to write “1”.

---

✔ You’re all set! This table now correctly shows both the generic formulas (using A and X) and the actual chemical formulas for each ionic compound.

Let me know if you want to practice naming them too!