Question

$\beta$-decay means emission of electron from

• A. innermost electron orbit
• B. a stable nucleus
• C. outermost electron orbit
• D. radioactive nucleus

Answer 1

Answer: (D)

$\beta$ - emission takes place from a radioactive nucleus a
${ }_{15}^{32} P \stackrel{\beta}{\rightarrow}{ }_{16}^{32} S+{ }_{-1} e^0+\bar{v}$
${ }_{15}^{32} P \stackrel{\beta}{\rightarrow}{ }_{16}^{32} S+{ }_{-1} e^0+\bar{v}$
where $\bar{v}$ is the anti-neutrino.
In $\beta^{+}$ decay a positron is emitted as
${ }_{11}^{22} N a \rightarrow_{11}^{22} N e+_{+1} e^{0}+v$
where $v$ is the neutrino.