12 3.2 Ionic Bonds and Electronegativity

Figures

Figure 3.2.1: Electronegativity of Elements

A diagram of the s and p blocks on the periodic table displaying the electronegativity values of the elements. The diagram has two large arrows indicating increasing electronegativity across the periodic table-the first arrow begins at the top left and goes to the right; and the second arrow starts from the bottom left and goes vertical to the top of the table. The electronegativity values decrease from flourine in group 7A which has the highest electronegativity at 3.98; moves down to francium in group 1 with the lowest at 0.7. Noble gases do not have an electronegativity value.

Figure 3.2.2: Formation of Magnesium Chloride

A lewis dot diagram of the the formation of magnesium chloride. To the left is a magnesium atom is shown with two valence electrons and two chlorine atoms each with seven valence electrons, indicated by lewis-dots. Red arrows show the movement of the two electrons from magnesium to the chlorine atoms. And on the right is the resulting ionic compound: the magnesium ion now labeled Mg2+, indicating it has lost two electrons, and each chlorine atom is now a chloride ion, labeled Cl-, indicating each has gained an extra electron, with a full outer shell depicted by lewis dots.

Practice questions

Multiple choice questions

1. Ca loses two electrons to acquire the electron configuration of Ar. What is the chemical symbol of the ion that it forms?
   1. Ca²⁻
   2. Ca²⁺
   3. Ca
   4. Ca⁺
2. Which of the following statements is incorrect?
   1. Metals tend to form cations.
   2. Nonmetals tend to form anions.
   3. The Octet rule states that atoms lose or gain electrons to acquire a completely filled valence shell that contains 8 electrons.
   4. Noble gases are very reactive due to their electron configurations.
3. What is the electron configuration of Mg²⁺?
   1. [latex]1s^{2}2s^{2}2p^{6}[/latex]
   2. [latex]1s^{2}2s^{2}2p^{6}3s^{2}[/latex]
   3. [latex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}[/latex]
   4. [latex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}[/latex]
4. What is the electron configuration of F⁻?
   1. [latex]1s^{2}2s^{2}2p^{5}[/latex]
   2. [latex]1s^{2}2s^{2}2p^{6}[/latex]
   3. [latex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}[/latex]
   4. [latex]1s^{2}[/latex]
5. What are the common ions formed by ²⁹Cu?
   1. Cu⁺ and Cu²⁺
   2. Cu⁺ and Cu³⁺
   3. Cu²⁺ and Cu³⁺
   4. Cu⁺, Cu²⁺ and Cu³⁺
6. What is the symbol of the ion formed by Beryllium losing two electrons from the valence shell?
   1. Be⁺
   2. Be²⁺
   3. Ba²⁺
   4. Ba⁺
7. Which of the following options incorrectly names the given polyatomic ion?
   1. CO₂^3- = Carbonate ion
   2. CH₃COO⁻ = Acetate ion
   3. CN⁻= Cyanide ion
   4. MnO₄^– = Manganese ion
8. What is the formula of the compound formed by NH₄⁺ and Cl⁻ ions?
   1. NH₄Cl
   2. NHCl₄
   3. ClNH₄
   4. NHCl
9. What is the chemical formula for calcium carbonate?
   1. CaCO₃
   2. CaCO
   3. CaO
   4. CaHCO₃
10. Which of the following options matches the name and the chemical formula?
    1. Ammonium carbonate: (NH₄)₂CO₃
    2. Magnesium hydroxide: MgOH
    3. Silver nitrate: AgNO
    4. Sodium hypochlorite: NaClO
11. Which of the following options gives the correct name for AuCl₃?
    1. Gold chloride
    2. Gold chloride (III)
    3. Gold (III) chloride
    4. Gold (III) chloride (III)

Solutions

1. b
2. d
3. a
4. b
5. a
6. b
7. d
8. a
9. a
10. a
11. c