Draw the Lewis Dot Diagram for the following atoms and ions: Aluminum (atom and ion )
The Correct Answer and Explanation is:
Lewis Dot Diagram for Aluminum (Al)
1. Aluminum Atom (Al):
Aluminum (Al) is an element with an atomic number of 13. This means that an aluminum atom has 13 electrons, with the electron configuration of:
- 1s² 2s² 2p⁶ 3s² 3p¹.
In the Lewis dot diagram, only the valence electrons (the electrons in the outermost shell) are represented. For aluminum, the valence electrons are in the 3rd energy level, specifically the 3s² and 3p¹ orbitals, which gives aluminum 3 valence electrons.
Lewis Dot Diagram for Al (atom):
Al: • • •The three dots represent the three valence electrons of aluminum. These are placed around the symbol for aluminum (Al).
2. Aluminum Ion (Al³⁺):
When aluminum forms a cation, it typically loses three electrons to achieve a stable electron configuration. Aluminum’s electron configuration in the ion state becomes:
- [Ne] 3s² 3p¹ → [Ne] (with the loss of 3 electrons).
Now, aluminum has no electrons in its valence shell and is left with an empty outer shell. The cation has a +3 charge due to the loss of three negatively charged electrons.
Lewis Dot Diagram for Al³⁺ (ion):
Al³⁺: [Ne] (No dots)
Since there are no valence electrons remaining, the Lewis dot diagram for the Al³⁺ ion has no dots around the symbol. The ion has an empty valence shell and carries a +3 charge.
Explanation:
Aluminum Atom (Al):
- The aluminum atom has 13 electrons, with 3 in the outermost shell, which are its valence electrons. In the Lewis dot diagram, we represent these electrons as dots around the chemical symbol, which helps in understanding how the atom will react or bond with other elements.
Aluminum Ion (Al³⁺):
- The Al³⁺ ion is formed when aluminum loses its 3 valence electrons to achieve a stable, noble gas electron configuration (similar to neon). The loss of these electrons gives the ion a +3 charge, and since there are no remaining valence electrons, the Lewis dot diagram does not display any dots around the symbol for Al³⁺.
This behavior aligns with the fact that metals like aluminum tend to lose electrons to achieve a stable, lower-energy configuration.