Describe the shapes of `BF_(3)` and `BH_(4)^(ө)`. Assign the hybridisation of boron in these species.

Explanation

To describe the shapes of \( BF_3 \) and \( BH_4^- \) and assign the hybridization of boron in these species, we can follow these steps:

### Step 1: Analyze \( BF_3 \)
- **Hybridization**: In \( BF_3 \), boron has three bonding pairs of electrons and no lone pairs. Therefore, the hybridization of boron in \( BF_3 \) is \( sp^2 \).
- **Shape**: The arrangement of the three bonding pairs of electrons around boron leads to a trigonal planar geometry. This means that the three fluorine atoms are positioned at the corners of an equilateral triangle, with boron at the center.

### Step 2: Analyze \( BH_4^- \)
- **Hybridization**: In \( BH_4^- \), boron has four bonding pairs of electrons and no lone pairs. The presence of the negative charge indicates that there is an additional electron, but it still contributes to the bonding pairs. Therefore, the hybridization of boron in \( BH_4^- \) is \( sp^3 \).
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