Write the Lewis structure for Al2O3 molecule
The correct answer and explanation is :
Lewis Structure of Al₂O₃
The Lewis structure of Al₂O₃ (aluminum oxide) consists of two aluminum (Al) atoms and three oxygen (O) atoms. Here’s a step-by-step breakdown of how to determine the Lewis structure of Al₂O₃.
Step-by-step Process:
- Determine the total number of valence electrons:
- Aluminum (Al) is in Group 13, so it has 3 valence electrons. Since there are 2 aluminum atoms, the total number of valence electrons contributed by aluminum is (2 \times 3 = 6).
- Oxygen (O) is in Group 16, so each oxygen atom has 6 valence electrons. Since there are 3 oxygen atoms, the total number of valence electrons contributed by oxygen is (3 \times 6 = 18).
- Therefore, the total number of valence electrons in Al₂O₃ is (6 + 18 = 24).
- Determine the bonding:
- Aluminum generally forms 3 bonds, and oxygen typically forms 2 bonds to complete its octet.
- The simplest arrangement would be placing aluminum atoms in the center with oxygen atoms bonded to them.
- Forming bonds:
- Each oxygen atom will form a double bond with each aluminum atom. In this way, each oxygen achieves an octet, and each aluminum atom completes its 3 bonds.
- Distribute remaining electrons:
- After the bonds are formed, all the 24 valence electrons are accounted for. Since oxygen atoms form double bonds with aluminum atoms, no lone pairs are left on the oxygen atoms, and all the valence electrons are involved in bonding.
Final Structure:
- The final Lewis structure for Al₂O₃ has two aluminum atoms each forming two double bonds with two oxygen atoms. Each oxygen atom shares two electrons with each aluminum atom. The aluminum atoms are surrounded by oxygen atoms, and the structure is ionic due to the difference in electronegativity between aluminum and oxygen, leading to partial charges.
Explanation of the Structure:
The structure of Al₂O₃ consists of a highly stable arrangement where the aluminum atoms form covalent bonds with the oxygen atoms. The oxidation states of aluminum are +3, and the oxidation states of oxygen are -2. This leads to a neutral compound with a simple molecular structure where the electrons are shared in a way that maximizes the stability of the atoms involved.