A number of elements are available in earth's crust but most abundant elements are___________

Options

A. Al and Fe
B. Al and Cu
C. Fe and Cu
D. Cu and Ag

Explanation

To answer the question regarding the most abundant elements in the Earth's crust, we can follow these steps:

### Step 1: Identify the Elements Present in the Earth's Crust
The Earth's crust is composed of a variety of elements. Some of the common elements found include Aluminium (Al), Iron (Fe), Copper (Cu), and Silver (Ag).

### Step 2: Determine the Abundance of Each Element
To find the most abundant elements, we need to look at their percentages by weight in the Earth's crust:
- Aluminium (Al) is approximately 8.3% by weight.
- Iron (Fe) is approximately 4.2% by weight.
- Copper (Cu) and Silver (Ag) are present but in much lower concentrations compared to Aluminium and Iron.

### Step 3: Compare the Abundance of Elements
From the percentages identified:
- Aluminium (8.3%) is the third most abundant element.
- Iron (4.2%) is also significant but less than Aluminium.
- Copper and Silver have lower percentages and are not considered abundant.

### Step 4: Conclusion
Based on the abundance percentages, the most abundant elements in the Earth's crust are Aluminium (Al) and Iron (Fe). Therefore, the correct answer is option 1: Aluminium and Iron.

### Final Answer
The most abundant elements in the Earth's crust are Aluminium and Iron (Al and Fe).

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