Aluminum Lewis Dot Structure

1.0Lewis Dot Structures

Lewis dot structures, also known as Lewis electron dot diagrams or electron dot structures, are a way to represent the valence electrons of an atom. They are fundamental in chemistry for understanding chemical bonding and the formation of molecules. For JEE aspirants, mastering Lewis structures is crucial for topics like chemical bonding and molecular geometry.

2.0What is a Lewis Dot Structure?

A Lewis dot structure shows an element's symbol surrounded by dots, where each dot represents a valence electron. Valence electrons are the electrons in the outermost shell of an atom and are involved in chemical bonding. The Lewis structure helps predict the number of bonds an atom can form.

3.0How to Draw the Lewis Dot Structure for Aluminium

Drawing the Lewis dot structure for any element, including aluminium (Al), is a simple process. It requires knowing the element's atomic number and its position in the periodic table to determine its valence electrons.

Valence Electrons of Aluminum

Aluminium is a metallic element with atomic number 13.

• Electronic Configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^1$
• Valence Electrons: The valence shell is the third shell (n=3). The electrons in this shell are the valence electrons. The number of valence electrons is the sum of electrons in the 3s and 3p orbitals, which is 2 + 1 = 3. Therefore, aluminum has 3 valence electrons.

Lewis Dot Structure of Aluminium Atom

To draw the Lewis dot structure for a neutral aluminum atom, follow these steps:

1. Write the chemical symbol for aluminum, which is Al.
2. Place three dots around the symbol to represent its three valence electrons.
3. The dots can be placed on any side of the symbol (top, bottom, left, or right), typically as single electrons before pairing them up.

Lewis Dot Structure of Aluminum Ion ($A{l}^{3+}$)

Aluminium is a metal and tends to lose its valence electrons to achieve a stable octet configuration (like the nearest noble gas, Neon).

• Formation of Ion: An aluminium atom loses its three valence electrons to form a positively charged ion, the aluminium ion $(A{l}^{3+})$.
• Lewis Structure of the Ion: The $(A{l}^{3+})$ ion has lost all of its valence electrons. Therefore, its Lewis dot structure is simply the symbol Al with a positive charge of +3 written as a superscript. There are no dots around the symbol.

4.0Lewis Dot Structure of Common Aluminum Compounds

The Lewis structure can also be drawn for molecules and ions containing aluminum.

• Aluminum Chloride$(AlC{l}_3)$: Aluminum shares its three valence electrons with three chlorine atoms to form covalent bonds. Each chlorine atom has seven valence electrons and shares one with aluminum to achieve an octet. However, the central Al atom in AlCl3​ is an exception to the octet rule as it has only six electrons.
• Aluminium Hydride$(Al{H}_3)$: Similar to aluminium, forms three single bonds with three hydrogen atoms. It is also an electron-deficient compound.