Formulas and Covalent Bonds Homework worksheet for chemistry students.

Problem Analysis:

The worksheet focuses on understanding chemical bonding, specifically ionic and covalent bonds, as well as writing formulas for compounds formed by different ions. Let's break it down step by step.

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Part 1: Fill in the Box

#### Instructions:
- Correctly fill in the box below.

#### Box Content:
1. Metals:
- Metals lose electrons and carry a positive charge.
- Group 1 (alkali metals) is the most willing to lose electrons.

2. Nonmetals:
- Nonmetals gain electrons and carry a negative charge.
- Group 17 (halogens) is the most willing to gain electrons.

#### Filled Box:
```
METALS lose electrons and carry a positive charge.
(Group 1 is the most willing to lose electrons)

NONMETALS gain electrons and carry a negative charge.
(Group 17 is the most willing to gain electrons)
```

---

Part 2: Write the Correct Formula for the Compounds

#### Instructions:
- Write the correct formula for the compounds that each of the following pairs of ions will make.

#### Rules for Writing Formulas:
1. The charges of the ions must balance to give an overall neutral compound.
2. Use subscripts to indicate the number of each ion needed to balance the charges.
3. If the subscript is "1," it is not written.

#### Solutions:
1. H⁺ F⁻:
- H has a +1 charge, and F has a -1 charge.
- They balance with a 1:1 ratio.
- Formula: HF

2. NH₄⁺ O²⁻:
- NH₄ has a +1 charge, and O has a -2 charge.
- To balance: 2(NH₄) → +2, 1(O) → -2.
- Formula: (NH₄)₂O

3. Mg²⁺ Cl⁻:
- Mg has a +2 charge, and Cl has a -1 charge.
- To balance: 1(Mg) → +2, 2(Cl) → -2.
- Formula: MgCl₂

4. Cu²⁺ I⁻:
- Cu has a +2 charge, and I has a -1 charge.
- To balance: 1(Cu) → +2, 2(I) → -2.
- Formula: CuI₂

5. Ba²⁺ CN⁻:
- Ba has a +2 charge, and CN has a -1 charge.
- To balance: 1(Ba) → +2, 2(CN) → -2.
- Formula: Ba(CN)₂

6. Ca²⁺ NO₃⁻:
- Ca has a +2 charge, and NO₃ has a -1 charge.
- To balance: 1(Ca) → +2, 2(NO₃) → -2.
- Formula: Ca(NO₃)₂

7. NH₄⁺ Cl⁻:
- NH₄ has a +1 charge, and Cl has a -1 charge.
- They balance with a 1:1 ratio.
- Formula: NH₄Cl

8. Sr²⁺ F⁻:
- Sr has a +2 charge, and F has a -1 charge.
- To balance: 1(Sr) → +2, 2(F) → -2.
- Formula: SrF₂

9. Mg²⁺ O²⁻:
- Mg has a +2 charge, and O has a -2 charge.
- They balance with a 1:1 ratio.
- Formula: MgO

10. Fe²⁺ Br⁻:
- Fe has a +2 charge, and Br has a -1 charge.
- To balance: 1(Fe) → +2, 2(Br) → -2.
- Formula: FeBr₂

11. Ca²⁺ OH⁻:
- Ca has a +2 charge, and OH has a -1 charge.
- To balance: 1(Ca) → +2, 2(OH) → -2.
- Formula: Ca(OH)₂

12. Ba²⁺ NO₃⁻:
- Ba has a +2 charge, and NO₃ has a -1 charge.
- To balance: 1(Ba) → +2, 2(NO₃) → -2.
- Formula: Ba(NO₃)₂

13. Al³⁺ SO₄²⁻:
- Al has a +3 charge, and SO₄ has a -2 charge.
- To balance: 2(Al) → +6, 3(SO₄) → -6.
- Formula: Al₂(SO₄)₃

14. Cr³⁺ O²⁻:
- Cr has a +3 charge, and O has a -2 charge.
- To balance: 2(Cr) → +6, 3(O) → -6.
- Formula: Cr₂O₃

15. Fe³⁺ O²⁻:
- Fe has a +3 charge, and O has a -2 charge.
- To balance: 2(Fe) → +6, 3(O) → -6.
- Formula: Fe₂O₃

16. Al³⁺ NO₃⁻:
- Al has a +3 charge, and NO₃ has a -1 charge.
- To balance: 1(Al) → +3, 3(NO₃) → -3.
- Formula: Al(NO₃)₃

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Part 3: Ionic and Covalent Bonds

#### Instructions:
- Ionic bonds are always formed between a metal and a nonmetal.
- Covalent bonds are ONLY formed between nonmetals.

#### Filled Boxes:
```
Ionic bonds are always formed between a metal and a nonmetal.
Covalent bonds are ONLY formed between nonmetals.
```

---

Part 4: Decide Whether the Following Compounds Contain Ionic (I) or Covalent (C) Bonds

#### Instructions:
- Determine whether each compound contains ionic (I) or covalent (C) bonds.

#### Rules:
1. Ionic Bonds: Formed between a metal and a nonmetal.
2. Covalent Bonds: Formed between two nonmetals.

#### Solutions:
1. HgO:
- Hg (mercury) is a metal, and O (oxygen) is a nonmetal.
- Ionic (I)

2. CCl₄:
- C (carbon) and Cl (chlorine) are both nonmetals.
- Covalent (C)

3. NaCl:
- Na (sodium) is a metal, and Cl (chlorine) is a nonmetal.
- Ionic (I)

4. AgI:
- Ag (silver) is a metal, and I (iodine) is a nonmetal.
- Ionic (I)

5. SiO₂:
- Si (silicon) and O (oxygen) are both nonmetals.
- Covalent (C)

6. CO:
- C (carbon) and O (oxygen) are both nonmetals.
- Covalent (C)

7. HgO:
- Hg (mercury) is a metal, and O (oxygen) is a nonmetal.
- Ionic (I)

8. CCl₄:
- C (carbon) and Cl (chlorine) are both nonmetals.
- Covalent (C)

9. NaCl:
- Na (sodium) is a metal, and Cl (chlorine) is a nonmetal.
- Ionic (I)

#### Final Answers:
```
HgO (I) CCl₄ (C) NaCl (I)
AgI (I) SiO₂ (C) CO (C)
HgO (I) CCl₄ (C) NaCl (I)
```

---

Final Answer:

\boxed{
\begin{array}{l}
\text{Part 1:} \\
\text{METALS lose electrons and carry a positive charge. (Group 1)} \\
\text{NONMETALS gain electrons and carry a negative charge. (Group 17)} \\
\\
\text{Part 2:} \\
\text{HF, (NH₄)₂O, MgCl₂, CuI₂, Ba(CN)₂, Ca(NO₃)₂, NH₄Cl, SrF₂, MgO, FeBr₂, Ca(OH)₂, Ba(NO₃)₂, Al₂(SO₄)₃, Cr₂O₃, Fe₂O₃, Al(NO₃)₃} \\
\\
\text{Part 3:} \\
\text{Ionic bonds are always formed between a metal and a nonmetal.} \\
\text{Covalent bonds are ONLY formed between nonmetals.} \\
\\
\text{Part 4:} \\
\text{HgO (I), CCl₄ (C), NaCl (I), AgI (I), SiO₂ (C), CO (C), HgO (I), CCl₄ (C), NaCl (I)}
\end{array}
}