What is the structure of `BrF_5`:

Options

A. Pentagonal bipyramidal
B. Octahedral
C. Square pyramidal
D. Bent T-shape

Explanation

To determine the structure of BrF₅ (Bromine pentafluoride), we can follow these steps:

### Step 1: Determine the Valence Electrons
Bromine (Br) is in Group 17 of the periodic table and has 7 valence electrons. Each fluorine (F) atom, which is in Group 17 as well, has 7 valence electrons. Since there are 5 fluorine atoms, we calculate the total number of valence electrons contributed by fluorine as follows:
\[ \text{Total valence electrons from F} = 5 \times 7 = 35 \]
Now, adding the valence electrons from bromine:
\[ \text{Total valence electrons} = 7 + 35 = 42 \]

### Step 2: Determine the Electron Domains
The total number of electron domains around the central bromine atom is calculated by considering the bonding pairs and lone pairs. In BrF₅, there are 5 bonding pairs (one for each Br-F bond) and no lone pairs on bromine. Thus, the total number of electron domains is:
\[ \text{Electron domains} = 5 \text{ (from Br-F bonds)} \]

### Step 3: Determine Hybridization
The hybridization can be determined based on the number of electron domains. For 5 electron domains, the hybridization is:
\[ \text{Hybridization} = sp³d \]

### Step 4: Determine the Geometry
With 5 electron domains, the geometry of the molecule is trigonal bipyramidal. However, we need to consider the arrangement of the atoms and lone pairs to determine the actual shape.

### Step 5: Identify the Shape
In BrF₅, there are 5 bonded fluorine atoms and no lone pairs on the bromine atom. The arrangement of the bonded atoms in a trigonal bipyramidal geometry will lead to a square pyramidal shape. The 5 fluorine atoms will occupy the equatorial and axial positions, with one lone pair at the apex.

### Final Structure
Thus, the structure of BrF₅ is square pyramidal.

### Summary of the Structure
- **Valence Electrons**: 42
- **Electron Domains**: 5
- **Hybridization**: sp³d
- **Geometry**: Trigonal bipyramidal
- **Shape**: Square pyramidal