On comparing the proportion of elements found in human tissue and Earth's crust, which one of the following is found to be negligible?

Options

A. Silicon
B. Calcium
C. Magnesium
D. Sulphur

Answer

To determine which element is found to be negligible in human tissue compared to its proportion in Earth's crust, we can follow these steps:

### Step 1: Identify the Elements and Their Proportions
We need to compare the proportions of the following elements in both human tissue and Earth's crust:
- Calcium
- Magnesium
- Sulfur
- Silicon

### Step 2: Gather Data on Proportions
Here are the approximate percentages of these elements in Earth's crust and human body:
- **Calcium**:
- Earth's crust: 3.6%
- Human body: 1.5%

- **Magnesium**:
- Earth's crust: 2.1%
- Human body: 0.1%

- **Sulfur**:
- Earth's crust: 0.3%
- Human body: 0.3%

- **Silicon**:
- Earth's crust: 27.7%
- Human body: negligible (close to 0%)

### Step 3: Analyze the Data
From the data, we can see:
- Calcium is present in both but is higher in Earth's crust.
- Magnesium is significantly lower in the human body compared to Earth's crust.
- Sulfur has equal proportions in both.
- Silicon is found in very high amounts in Earth's crust but is negligible in human tissue.

### Step 4: Conclusion
Based on the analysis, the element that is found to be negligible in human tissue compared to its significant presence in the Earth's crust is **Silicon**.

### Final Answer
The answer is **Silicon**.

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