The ratio between the neutrons in C and Si with respect to atomic masses 12 and 28 is:

Options

A. `2:3`
B. `3:2`
C. `3:7`
D. `7:3`

Explanation

To find the ratio between the neutrons in carbon (C) and silicon (Si) based on their atomic masses (12 for carbon and 28 for silicon), follow these steps:

### Step 1: Identify the Atomic Mass and Atomic Number
- The atomic mass of carbon (C) is 12.
- The atomic mass of silicon (Si) is 28.
- The atomic number of carbon (C) is 6 (which indicates the number of protons).
- The atomic number of silicon (Si) is 14 (which indicates the number of protons).

### Step 2: Calculate the Number of Neutrons
The number of neutrons in an element can be calculated using the formula:
\[ \text{Number of Neutrons} = \text{Atomic Mass} - \text{Atomic Number} \]

**For Carbon (C):**
- Number of Neutrons in C = Atomic Mass of C - Atomic Number of C
- Number of Neutrons in C = 12 - 6 = 6

**For Silicon (Si):**
- Number of Neutrons in Si = Atomic Mass of Si - Atomic Number of Si
- Number of Neutrons in Si = 28 - 14 = 14

### Step 3: Write the Ratio of Neutrons
Now that we have the number of neutrons for both elements:
- Neutrons in C = 6
- Neutrons in Si = 14

The ratio of neutrons in carbon to silicon is:
\[ \text{Ratio} = \frac{\text{Neutrons in C}}{\text{Neutrons in Si}} = \frac{6}{14} \]

### Step 4: Simplify the Ratio
To simplify the ratio \( \frac{6}{14} \):
- Divide both the numerator and the denominator by their greatest common divisor (GCD), which is 2.
- \( \frac{6 \div 2}{14 \div 2} = \frac{3}{7} \)

### Final Answer
The ratio of neutrons in carbon to silicon is:
\[ 3 : 7 \]

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