Question

An atomic nucleus $A$ is composed of $84$ protons and $128$ neutrons. the nucleus $A$ emits an alpha particle and is transformed into nucleus $B$. the nucleus $B$ emits a beta particles and is transformed into a nucleus $C$ ? Does the composition of nucleus $C$ changes if it emits gamma radiations?

Answer 1

Step :1 Given data

Number of protons of nucleus $\text{'}A\text{'}$ is $84$ .

Number of neutron of nucleus $\text{'}A\text{'}$ is $128$.

Step: 2 Finding mass number of nucleus A

$\begin{array}{rcl}MassnumberofnucleusA& =& numberofprotons+numberofneutrons\\ 84+128& =& 212\end{array}$

Step:3 write the nuclear equation

we know that emission of $\alpha$-particles mass number decrease by $4$ units and atomic number decreases by $2$units

$\alpha$-particles symbol ${}_2{}^{4}H{e}^{}$

So ${}_{84}A^{212}\to {}_{82}B^{208}+{}_2{}^{4}H{e}^{}$

Now nucleus B emits a beta particles and transformed into a nucleus $C$.

Emission of $\beta$-particles mass number remains same but number of protons increases by one units.

${}_{82}B^{208}\to {}_{83}C^{198}+{}_{-1}{}^0\beta$

Hence, composition of nucleus is $83$ protons and $115$neutrons.

Nucleolus $C$ emits gamma $\left(\gamma \right)$ ray.

Emission of $\gamma$-ray mass number and atomic numbers of nucleolus does not change.

Hence, composition of $C$ does not changes.