Q173 / 180 · COMEDK 2026 (9 May Shift 1) · Physics
A mercury-198 nucleus is bombarded by a neutron, which causes a nuclear reaction
${}^{1}_{0}n + {}^{198}_{80}Hg \longrightarrow {}^{197}_{79}Au + X$
What is the unknown product particle X?
${}^{1}_{0}n + {}^{198}_{80}Hg \longrightarrow {}^{197}_{79}Au + X$
What is the unknown product particle X?
- AAlpha particle
- BProton
- CBeta particle
- Correct answerDDeuteron
Solution
Let the unknown particle $X$ be represented as ${}^{A}_{Z}X$.
Applying the principle of conservation of mass number:
$1 + 198 = 197 + A$
$199 = 197 + A$
$A = 2$
Applying the principle of conservation of atomic number:
$0 + 80 = 79 + Z$
$80 = 79 + Z$
$Z = 1$
The particle with mass number $A = 2$ and atomic number $Z = 1$ is ${}^{2}_{1}H$, which is a deuteron.
Answer: Deuteron
Applying the principle of conservation of mass number:
$1 + 198 = 197 + A$
$199 = 197 + A$
$A = 2$
Applying the principle of conservation of atomic number:
$0 + 80 = 79 + Z$
$80 = 79 + Z$
$Z = 1$
The particle with mass number $A = 2$ and atomic number $Z = 1$ is ${}^{2}_{1}H$, which is a deuteron.
Answer: Deuteron
Hence, the correct answer is option: 'D'.