Molecular Geometry and Valence Electrons

This video tutorial explains how to write the Lewis structure for the AlF4- ion. It begins by counting the valence electrons of aluminum and fluorine, considering the extra electron due to the negative charge. The video then demonstrates constructing the Lewis structure by placing aluminum at the center and arranging four fluorine atoms around it, ensuring each atom achieves an octet. The molecular geometry is identified as tetrahedral, with a bond angle of 109.5°, confirmed using AXE notation. The tutorial concludes with a summary of the structure and geometry of AlF4-.

How many valence electrons does aluminum contribute in the AlF4- ion?

• 1

• 3

• 7

• 5

What is the total number of valence electrons in the AlF4- ion?

• 28

• 30

• 32

• 34

Which element is placed at the center of the Lewis structure for AlF4-?

• Nitrogen

• Aluminum

• Oxygen

• Fluorine

How many fluorine atoms are bonded to the central aluminum atom in AlF4-?

• 5

• 4

• 3

• 2

What is the purpose of placing brackets around the Lewis structure of AlF4-?

• To denote a covalent bond

• To highlight the central atom

• To show it is an ion

• To indicate it is a molecule

What is the molecular geometry of the AlF4- ion?

• Tetrahedral

• Bent

• Trigonal Planar

• Linear

What is the bond angle in the tetrahedral geometry of AlF4-?

• 180°

• 109.5°

• 90°

• 120°

How many lone pairs are present on the central aluminum atom in AlF4-?

• 3

• 2

• 1

• 0

In AXE notation, what does 'X' represent for AlF4-?

• Total number of electrons

• Type of central atom

• Number of atoms bonded to the central atom

• Number of lone pairs

What is the electron geometry of AlF4-?

• Octahedral

• Linear

• Tetrahedral

• Trigonal Planar