Chem Lesson 3.2b HW

1. Write the formula for strontium chloride

Strontium has a +2 charge and chlorine is -1. You need 2 chloride ions to balance the 1 strontium.

Explanation

Strontium has a +2 charge and chlorine is -1. You need 2 chloride ions to balance the 1 strontium.

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3. What is the formula of aluminum oxide?

Aluminum is +3 charge. Oxygen is -2 charge. If they both totaled 6, they could balance each other. 2 aluminums (at +3 each) total +6. 3 oxides (at -2 each) total -6. BOOM!! BALANCED!!

Explanation

Aluminum is +3 charge. Oxygen is -2 charge. If they both totaled 6, they could balance each other. 2 aluminums (at +3 each) total +6. 3 oxides (at -2 each) total -6. BOOM!! BALANCED!!

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7. Identify the element in Period 3 of the Periodic Table that reacts with oxygen to form an ionic compound represented by the formula X2O. [1]

sodium is the only Period 3 element that has 1 valence electron. Oxide ions have a charge of -2, which is balanced by 2 X ions, each with a +1 charge.

Explanation

sodium is the only Period 3 element that has 1 valence electron. Oxide ions have a charge of -2, which is balanced by 2 X ions, each with a +1 charge.

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9. Explain, in terms of electrons, why the ionic radius of a Group 2 element is smaller than its atomic radius. [1]

The ionic radius of a Group 2 element is smaller than its atomic radius because it loses valence electrons. When a Group 2 element forms an ion, it loses two valence electrons, resulting in a decrease in the electron cloud surrounding the nucleus. This loss of electrons reduces the size of the ion compared to the neutral atom, leading to a smaller ionic radius. Additionally, the ion has more protons than electrons, which further contributes to the reduction in size. The terms "fewer electron orbitals," "lost valence electrons," "fewer valence electrons," "more protons than electrons," and "lost an electron orbital" all explain why the ionic radius is smaller. The terms "fewer electrons" and "less electrons" also imply the loss of valence electrons.

Explanation

The ionic radius of a Group 2 element is smaller than its atomic radius because it loses valence electrons. When a Group 2 element forms an ion, it loses two valence electrons, resulting in a decrease in the electron cloud surrounding the nucleus. This loss of electrons reduces the size of the ion compared to the neutral atom, leading to a smaller ionic radius. Additionally, the ion has more protons than electrons, which further contributes to the reduction in size. The terms "fewer electron orbitals," "lost valence electrons," "fewer valence electrons," "more protons than electrons," and "lost an electron orbital" all explain why the ionic radius is smaller. The terms "fewer electrons" and "less electrons" also imply the loss of valence electrons.

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10. Which type of bond is formed when electrons are transferred from one atom to another?

Covalent

Hydrogen

Metallic

Ionic

The only type of bond we have talked about so far is IONIC. Besides, the metals lose their electrons to nonmetals, which is what happens during ionic bond formation.

Explanation

The only type of bond we have talked about so far is IONIC. Besides, the metals lose their electrons to nonmetals, which is what happens during ionic bond formation.

11. Which Lewis electron-dot structure is drawn correctly for the atom it represents?

Neon has 8 valence electrons. 8 dots match the 8 valence electrons.

Explanation

Neon has 8 valence electrons. 8 dots match the 8 valence electrons.

12. Which element forms an ionic compound when it reacts with lithium?

K

Fe

Kr

Br

Bromine (Br) forms an ionic compound when it reacts with lithium. This is because bromine is a halogen and has a tendency to gain one electron to achieve a stable octet configuration. Lithium, on the other hand, has a tendency to lose one electron. Therefore, when lithium reacts with bromine, lithium loses one electron and bromine gains one electron, resulting in the formation of an ionic compound.

Explanation

Bromine (Br) forms an ionic compound when it reacts with lithium. This is because bromine is a halogen and has a tendency to gain one electron to achieve a stable octet configuration. Lithium, on the other hand, has a tendency to lose one electron. Therefore, when lithium reacts with bromine, lithium loses one electron and bromine gains one electron, resulting in the formation of an ionic compound.