The average binding energy of a nucleon inside an atomic nucleus is about 

1. 8 MeV

2. 8 eV

3. 8 J 

4. 8 erg

A nucleus with Z = 92 emits the following in a sequence:

$\alpha ,<mspace\; width="1em"></mspace>{\beta }^{-},<mspace\; width="1em"></mspace>{\beta }^{-},<mspace\; width="1em"></mspace>\alpha ,<mspace\; width="1em"></mspace>\alpha ,<mspace\; width="1em"></mspace>\alpha ,<mspace\; width="1em"></mspace>\alpha ,<mspace\; width="1em"></mspace>\alpha ,<mspace\; width="1em"></mspace>{\beta }^{-},{\beta }^{-},<mspace\; width="1em"></mspace>\alpha ,<mspace\; width="1em"></mspace>{\beta }^{+},<mspace\; width="1em"></mspace>{\beta }^{+},<mspace\; width="1em"></mspace>\alpha$. The Z of the resulting nucleus is [AIEEE 2003]

1. 74 

2. 76 

3. 78

4. 82

In nuclear fission, the percentage of mass converted into energy is about

1.  1%

2.  0.1%

3.  0.01%

4.  10%

The mass number of helium is 4 and that for suphur is 32. The radius of sulphur nuclei is larger than that of helium by

1.  $\sqrt{8}$

2.  4

3.  2

4.  8

In the nuclear decay given below

${}_{\mathrm{z}}{}^{\mathrm{A}}\mathrm{X}<mspace\; width="1em"></mspace>\stackrel{}{\to }<mspace\; width="1em"></mspace>{}_{\mathrm{Z}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>1}{}^{\mathrm{A}}\mathrm{Y}<mspace\; width="1em"></mspace>\stackrel{}{\to }<mspace\; width="1em"></mspace>{}_{\mathrm{Z}<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>1}{}^{\mathrm{A}<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>4}\mathrm{B}_{*}<mspace\; width="1em"></mspace>\stackrel{}{\to }<mspace\; width="1em"></mspace>{}_{\mathrm{Z}<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>1}{}^{\mathrm{A}<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>4}\mathrm{B},$

$\mathrm{The}<mspace\; width="1em"></mspace>\mathrm{particles}<mspace\; width="1em"></mspace>\mathrm{emitted}<mspace\; width="1em"></mspace>\mathrm{in}<mspace\; width="1em"></mspace>\mathrm{the}<mspace\; width="1em"></mspace>\mathrm{sequence}<mspace\; width="1em"></mspace>\mathrm{are}<mspace\; width="1em"></mspace>$
$$

1.  $\mathrm{\beta },<mspace\; width="1em"></mspace>\mathrm{\alpha },<mspace\; width="1em"></mspace>\mathrm{\gamma }<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

2.  $\mathrm{\gamma },<mspace\; width="1em"></mspace>\mathrm{\beta },<mspace\; width="1em"></mspace>\mathrm{\alpha }<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

3.  $\mathrm{\beta },<mspace\; width="1em"></mspace>\mathrm{\gamma },<mspace\; width="1em"></mspace>\mathrm{\alpha }<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

4.  $\mathrm{\alpha },<mspace\; width="1em"></mspace>\mathrm{\beta },<mspace\; width="1em"></mspace>\mathrm{\gamma }$

$In<mspace\; width="1em"></mspace>the<mspace\; width="1em"></mspace>nucleus<mspace\; width="1em"></mspace>of<mspace\; width="1em"></mspace>{}_{11}{}^{23}Na,<mspace\; width="1em"></mspace>\mathrm{the}<mspace\; width="1em"></mspace>\mathrm{number}<mspace\; width="1em"></mspace>\mathrm{of}<mspace\; width="1em"></mspace>\mathrm{protons},<mspace\; width="1em"></mspace>\mathrm{neutrons}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>\mathrm{electrons}<mspace\; width="1em"></mspace>\mathrm{are}$:

1.  11, 12, 0

2.  23, 12, 11

3.  12, 11, 0

4.  23, 11, 12

A thorium nucleus is formed when a uranium nucleus emits an $\mathrm{\alpha }<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>\mathrm{particle}$. The atomic number of thorium is

1.  92

2.  90

3.  82

4.  94

The activity of the radioactive element decreases to one-third of the original activity ${\mathrm{A}}_0$ in a period of 7 years. After a further lapse of 7 years, its activity will be:

1.  ${\mathrm{A}}_0$ $$ $$

2.  $\frac{2}{3}{\mathrm{A}}_0$ $$ $$

3.  $\frac{{\mathrm{A}}_0}{6}$ $$ $$

4.  $\frac{{\mathrm{A}}_0}{9}$

The radius of Germanium (Ge) nuclide is measured to be twice the radius of ${}_4{}^9\mathrm{Be}$. The number of nucleons in Ge is:

1. 73

2. 74

3. 75

4. 72