Draw the Lewis dot structure of each atom, ions, the resulting molecule, and the corresponding Molecular Formula. 1.) Potassium and Iodine
The Correct Answer and Explanation is:
Lewis Dot Structure of Potassium (K) and Iodine (I)
1. Potassium (K)
Potassium (K) is an alkali metal in group 1 of the periodic table. It has one valence electron in its outer shell. The electron configuration for potassium is:
- K: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
In the Lewis dot structure, we represent the valence electron as a single dot around the symbol for potassium:
- K: • (one dot represents the single valence electron).
2. Iodine (I)
Iodine (I) is a halogen in group 17 of the periodic table. It has seven valence electrons. The electron configuration for iodine is:
- I: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁵
In the Lewis dot structure, iodine has seven valence electrons, represented as seven dots around the symbol for iodine:
- I: • • • • • • • (seven dots).
Formation of Iodine Ion (I⁻)
When iodine reacts with potassium, it gains one electron to form an iodide ion (I⁻). This results in the following Lewis structure for the iodide ion:
- I⁻: • • • • • • • • (eight dots, representing a full octet).
Potassium Ion (K⁺):
When potassium reacts with iodine, it loses its one valence electron, resulting in the formation of a potassium ion (K⁺). The potassium ion has no dots around it:
- K⁺: (no dots, representing the loss of the single valence electron).
Resulting Ionic Compound: Potassium Iodide (KI)
When potassium and iodine react, the potassium atom donates its valence electron to the iodine atom. The potassium ion (K⁺) and the iodide ion (I⁻) are then attracted to each other by electrostatic forces, forming an ionic bond. This results in the formation of potassium iodide (KI), an ionic compound.
Molecular Formula of Potassium Iodide (KI):
- The molecular formula for this compound is KI, which indicates one potassium ion combined with one iodide ion.
Explanation:
- Potassium (K), being in group 1, has one electron in its outer shell, which it readily loses to achieve a stable electron configuration similar to the noble gases.
- Iodine (I), being in group 17, needs one electron to complete its octet and become stable, so it gains the electron from potassium.
- The resulting K⁺ ion and I⁻ ion are oppositely charged and are held together by ionic bonds, resulting in the formation of potassium iodide (KI).
- Potassium iodide is a neutral compound with the molecular formula KI, as the positive charge on the potassium ion is balanced by the negative charge on the iodide ion.
