Question

When \({}^{10}_{5}\text{B}\) nuclei are bombarded by neutrons, one of the resultant nuclei is \({}^{7}_{3}\text{Li}\). Then the emitted particle will be:

• A. Alpha particle
• B. Neutrons
• C. Gamma particle
• D. Beta particle

Hint:

Always use conservation of mass number and atomic number to identify unknown particles in nuclear reactions.

Answer 1

The Correct Option is A

Step 1: Write the nuclear reaction.
\[ {}^{10}_{5}\text{B} + {}^{1}_{0}n \rightarrow {}^{7}_{3}\text{Li} + X \]

Step 2: Apply conservation of mass number.
\[ 10 + 1 = 7 + A_X \]
\[ 11 = 7 + A_X \]
\[ A_X = 4 \]

Step 3: Apply conservation of atomic number.
\[ 5 + 0 = 3 + Z_X \]
\[ 5 = 3 + Z_X \]
\[ Z_X = 2 \]

Step 4: Identify the particle.
The particle with mass number \(4\) and atomic number \(2\) is:
\[ {}^{4}_{2}\text{He} \]

Step 5: Recognize the particle type.
\({}^{4}_{2}\text{He}\) nucleus is an alpha particle.

Step 6: Interpretation.
Thus, neutron bombardment of boron results in lithium and an alpha particle.

Step 7: Final answer.
\[ \boxed{\text{Alpha particle}} \]