The order of abundance of IIIA group elements is

Options

A. `Al gt Ga gt B`
B. `B gt Ga gt Al`
C. `B gt Al gt Ga`
D. `Ga gt Al gt B`

Answer

To determine the order of abundance of the IIIA group elements (Boron Family) in the Earth's crust, we will analyze the abundance percentages of each element in this group.

### Step-by-Step Solution:

1. **Identify the IIIA Group Elements**: The elements in the IIIA group (or group 13) of the periodic table include Boron (B), Aluminium (Al), Gallium (Ga), Indium (In), and Thallium (Tl). However, we will focus on the most abundant ones in the Earth's crust: Boron, Aluminium, and Gallium.

2. **Find the Abundance Percentages**:
- **Aluminium (Al)**: The abundance of Aluminium in the Earth's crust is approximately **8.1%**.
- **Gallium (Ga)**: The abundance of Gallium in the Earth's crust is approximately **0.00119%**.
- **Boron (B)**: The abundance of Boron in the Earth's crust is approximately **0.00086%**.

3. **Rank the Elements by Abundance**:
- From the percentages, we can rank the elements:
- **1st**: Aluminium (8.1%)
- **2nd**: Gallium (0.00119%)
- **3rd**: Boron (0.00086%)

4. **Conclusion**: The order of abundance of the IIIA group elements in the Earth's crust is:
- **Aluminium > Gallium > Boron**.

### Final Answer:
The order of abundance of IIIA group elements is Aluminium, Gallium, Boron.