What is the expected geometry of `AsF_(5)` molecule ?

Answer

To determine the expected geometry of the AsF₅ molecule, we can follow these steps:

### Step 1: Determine the Valence Electrons
Arsenic (As) is in Group 15 of the periodic table and has 5 valence electrons. Each fluorine (F) atom has 7 valence electrons, but in this case, we are interested in the bonding electrons.

### Step 2: Count the Total Number of Valence Electrons
In AsF₅, there is one arsenic atom and five fluorine atoms. Therefore, the total number of valence electrons is:
- Arsenic: 5 electrons
- Fluorine: 5 × 7 = 35 electrons

However, since each fluorine atom will form a single bond with arsenic, we will only consider the bonding electrons:
- Total bonding electrons = 5 (from As) + 5 (from 5 F) = 10 electrons (5 bonds)

### Step 3: Determine the Bonding Arrangement
In AsF₅, arsenic will form five single bonds with the five fluorine atoms. This means there are five bond pairs and no lone pairs on the arsenic atom.

### Step 4: Apply VSEPR Theory
According to VSEPR (Valence Shell Electron Pair Repulsion) theory, the geometry of a molecule is determined by the repulsion between electron pairs. For a central atom with five bond pairs and no lone pairs, the geometry is classified as trigonal bipyramidal.

### Step 5: Visualize the Geometry
In a trigonal bipyramidal geometry:
- Three fluorine atoms will occupy the equatorial positions (120° apart).
- Two fluorine atoms will occupy the axial positions (180° apart).

### Conclusion
The expected geometry of the AsF₅ molecule is trigonal bipyramidal.

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