Ne nucleus , the after absorbing energy , decays into two `alpha` particle and an unknown nucleus . The unknown nucleus is

Options

A. Nitrogen
B. Carbon
C. Boron
D. Oxygen

Answer

To solve the problem, we need to determine the unknown nucleus that results from the decay of a neon nucleus into two alpha particles. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the properties of the Neon nucleus
- The atomic number (Z) of Neon (Ne) is 10.
- The mass number (A) of Neon is 22.

### Step 2: Write down the decay reaction
The decay of the Neon nucleus can be represented as:
\[ \text{Ne} \rightarrow 2 \alpha + X \]
where \( X \) is the unknown nucleus.

### Step 3: Determine the properties of the alpha particle
An alpha particle is equivalent to a helium nucleus, which has:
- Atomic number (Z) = 2
- Mass number (A) = 4

### Step 4: Calculate the atomic number of the unknown nucleus \( X \)
The total atomic number before and after the decay must be conserved. Therefore, we can set up the equation:
\[ Z_{\text{Ne}} = 2 \times Z_{\alpha} + Z_X \]
Substituting the known values:
\[ 10 = 2 \times 2 + Z_X \]
\[ 10 = 4 + Z_X \]
\[ Z_X = 10 - 4 = 6 \]

### Step 5: Calculate the mass number of the unknown nucleus \( X \)
Similarly, we can apply the conservation of mass number:
\[ A_{\text{Ne}} = 2 \times A_{\alpha} + A_X \]
Substituting the known values:
\[ 22 = 2 \times 4 + A_X \]
\[ 22 = 8 + A_X \]
\[ A_X = 22 - 8 = 14 \]

### Step 6: Identify the unknown nucleus
Now we have:
- Atomic number \( Z_X = 6 \)
- Mass number \( A_X = 14 \)

Referring to the periodic table, the element with atomic number 6 is Carbon (C), and its most common isotope has a mass number of 14.

### Final Answer
The unknown nucleus is Carbon (C).

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