Educational worksheet for students to practice writing chemical formulas and identifying compounds as ionic or covalent.

Here is the step-by-step solution to fill in the chart.

Step 1: Determine if it is Ionic or Covalent

* Ionic: Made of a Metal and a Non-metal (or contains Polyatomic Ions like Nitrate, Sulfate, etc.). Metals lose electrons (+) and Non-metals gain electrons (-).
* Covalent: Made of two Non-metals. They share electrons. We use prefixes (mono-, di-, tri-) to tell us how many atoms there are.

Step 2: Write the Chemical Formula

* For Ionic Compounds: Balance the positive and negative charges so the total is zero.
* *Example:* Aluminum is $Al^{+3}$ and Chloride is $Cl^{-1}$. You need three chlorides to balance one aluminum. Formula: $AlCl_3$.
* For Covalent Compounds: Translate the prefixes directly into subscripts (numbers at the bottom right).
* *Example:* "Di" means 2, "Tri" means 3. Carbon dioxide = $CO_2$.

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Detailed Breakdown for Each Row:

1. Potassium chloride
* Potassium (Metal, Group 1) is $K^+$. Chlorine (Non-metal, Group 17) is $Cl^-$.
* Charges +1 and -1 balance perfectly.
* Type: Ionic | Formula: KCl

2. Sulfur trioxide
* Sulfur and Oxygen are both Non-metals.
* "Tri-" means 3 oxygens. No prefix on Sulfur means 1 sulfur.
* Type: Covalent | Formula: SO₃

3. Dinitrogen monoxide
* Nitrogen and Oxygen are Non-metals.
* "Di-" means 2 nitrogens. "Mon-" means 1 oxygen.
* Type: Covalent | Formula: N₂O

4. Calcium oxide
* Calcium (Metal, Group 2) is $Ca^{2+}$. Oxygen (Non-metal, Group 16) is $O^{2-}$.
* Charges +2 and -2 balance perfectly.
* Type: Ionic | Formula: CaO

5. Aluminum chloride
* Aluminum (Metal, Group 13) is $Al^{3+}$. Chlorine is $Cl^-$.
* You need three $Cl^-$ to balance one $Al^{3+}$.
* Type: Ionic | Formula: AlCl₃

6. Carbon tetrachloride
* Carbon and Chlorine are Non-metals.
* "Tetra-" means 4 chlorines.
* Type: Covalent | Formula: CCl₄

7. Sodium bromide
* Sodium (Metal, Group 1) is $Na^+$. Bromine (Non-metal, Group 17) is $Br^-$.
* Charges +1 and -1 balance.
* Type: Ionic | Formula: NaBr

8. Sodium oxide
* Sodium is $Na^+$. Oxygen is $O^{2-}$.
* You need two $Na^+$ (+2 total) to balance one $O^{2-}$ (-2 total).
* Type: Ionic | Formula: Na₂O

9. Carbon monoxide
* Carbon and Oxygen are Non-metals.
* "Mon-" means 1 oxygen.
* Type: Covalent | Formula: CO

10. Dinitrogen trioxide
* Nitrogen and Oxygen are Non-metals.
* "Di-" means 2 nitrogens. "Tri-" means 3 oxygens.
* Type: Covalent | Formula: N₂O₃

11. Sodium chloride
* Sodium is $Na^+$. Chlorine is $Cl^-$.
* Type: Ionic | Formula: NaCl

12. Iodine pentachloride
* Iodine and Chlorine are Non-metals.
* "Penta-" means 5 chlorines.
* Type: Covalent | Formula: ICl₅

13. Silicon dioxide
* Silicon and Oxygen are Non-metals (Metalloid acting as non-metal here).
* "Di-" means 2 oxygens.
* Type: Covalent | Formula: SiO₂

14. Diphosphorus trioxide
* Phosphorus and Oxygen are Non-metals.
* "Di-" means 2 phosphorus. "Tri-" means 3 oxygens.
* Type: Covalent | Formula: P₂O₃

15. Magnesium oxide
* Magnesium (Metal, Group 2) is $Mg^{2+}$. Oxygen is $O^{2-}$.
* Charges +2 and -2 balance.
* Type: Ionic | Formula: MgO

16. Magnesium chloride
* Magnesium is $Mg^{2+}$. Chlorine is $Cl^-$.
* You need two $Cl^-$ to balance one $Mg^{2+}$.
* Type: Ionic | Formula: MgCl₂

17. Phosphorus trichloride
* Phosphorus and Chlorine are Non-metals.
* "Tri-" means 3 chlorines.
* Type: Covalent | Formula: PCl₃

18. Dinitrogen pentoxide
* Nitrogen and Oxygen are Non-metals.
* "Di-" means 2 nitrogens. "Penta-" means 5 oxygens.
* Type: Covalent | Formula: N₂O₅

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Final Answer:

| Chemical Name | Ionic or Covalent | Chemical Formula |
| :--- | :--- | :--- |
| Potassium chloride | Ionic | KCl |
| Sulfur trioxide | Covalent | SO₃ |
| Dinitrogen monoxide | Covalent | N₂O |
| Calcium oxide | Ionic | CaO |
| Aluminum chloride | Ionic | AlCl₃ |
| Carbon tetrachloride | Covalent | CCl₄ |
| Sodium bromide | Ionic | NaBr |
| Sodium oxide | Ionic | Na₂O |
| Carbon monoxide | Covalent | CO |
| Dinitrogen trioxide | Covalent | N₂O₃ |
| Sodium chloride | Ionic | NaCl |
| Iodine pentachloride | Covalent | ICl₅ |
| Silicon dioxide | Covalent | SiO₂ |
| Diphosphorus trioxide | Covalent | P₂O₃ |
| Magnesium oxide | Ionic | MgO |
| Magnesium chloride | Ionic | MgCl₂ |
| Phosphorus trichloride | Covalent | PCl₃ |
| Dinitrogen pentoxide | Covalent | N₂O₅ |