Nuclei practice · Mixed difficulty

A radioactive element ${}_{92}^{238}U$ undergoes successive radioactive decay and decays into ${}_{82}^{206}Pb$.The number of $\alpha\,\, \mathrm{ }and\mathrm{ }\,\,\beta$ particles emitted respectively are:

A radioactive decay chain starts from $_{92}N{p^{237}}$ produces $_{90}T{h^{229}}$ by successive emissions. The emitted particles can be

By how much fraction energy will be decreased in a given atomic explosion, if the speed of light were become $1 / 3$ of the present value?

${r_1}\,\,\,{\text{and}}\,\,\,{r_2}$ are the radii of atomic nuclei of mass number 125 and 216 respectively. The ratio of $\frac{{{r_1}}}{{{r_2}}}$ is

An element $A$ decays into element $C$ by a two step process
$A \to B{ + _2}\mathrm{H}{\mathrm{e}^4}$
$B \to C + {2_{ - 1}}\,\,{e^0}$
Then

For ${l^{131}}$, half life is 8 days, the activity of an $8\,\mu g$ sample of l is

A free neutron decays spontaneously into

The mass number of nucleus having radius equal
to half of the radius of nucleus with mass number
192 is

In the nuclear reaction: $X{\left( {n,\alpha } \right)_3}L{i^7}$ the term $X$ will be

The rest energy of an electron is

The subatomic particles proton and neutron fall under the group of

Let ${A}_{{n}}$ be the area enclosed by the ${n}$th orbit in a hydrogen atom. The graph of $\ln \left(\frac{{A_n}}{{A_1}}\right)$ against $\ln {(n})$

A sample of radioactive material can decay by two processes $A$ and $B$ with half-lives $\frac{1}{2}$ hour and $\frac{1}{4}$ bour respectively. Now, the radioactive sample decays for 7 hour in such a way that for 1 hour it decays according to process ${A}$ and for next hour decays according to ${B}$ and this decaying with different processes in alternate hours continues upto 6 hour and then, in $7^{\text {th}}$ hour, it decays simultaneously with both the processes. If ${N}_0$ nuclei of sample are present at $t=0$, then number of radioactive nuclei after 7 hour would be

The number of revolutions per second made by an electron in the first Bohr orbit of hydrogen atom is of the order of

For uranium nucleus how does its mass vary with volume?

From the statements given below:
(A) The angular momentum of an electron in $n^{\text {th}}$ orbit is an integral multiple of $h$.
(B) Nuclear forces do not obey inverse square law.
(C) Nuclear forces are spin dependent.
(D) Nuclear forces are central and charge independent.
(E) Stability of nucleus is inversely proportional to the value of packing fraction.
Choose the correct answer from the options given below:

A freshly prepared radioactive sample having half life 4 hours, emits radiation of intensity which is 64 times the permissible level. The minimum time in hours after which it is safe to work with the source will be

The end product of the decay of $_{90}\mathrm{T}{\mathrm{h}^{232}}\,\,\mathrm{is}\,{\,_{82}}\mathrm{P}{\mathrm{b}^{208}}$. The number of $\alpha \,\,\mathrm{and}\,\,\beta$-particles emitted are respectively

A nucleus $_z{X^A}$ emits an $\mathrm{\alpha }$-particle. The resultant nucleus emits a ${\mathrm{\beta }^ + }$ particle. The respective atomic and mass numbers of the final nucleus will be

If $M$ is the atomic mass and $A$ is the mass number, packing fraction is given by

The fussion process is possible at high temperatures, because at higher temperatures

Pick out the correct statement from the following.

Binding energy of a certain nucleus is $18 \times 10^8 \mathrm{~J}$. How much is the difference between total mass of all the nucleons and nuclear mass of the given nucleus:

The velocity of alpha particles from polonium (atomic weight 210) is $1.6 \times 10^7 \mathrm{~m} / \mathrm{sec}$. What is the velocity of recoil atoms?

Atomic number of a nucleus is $Z$ and atomic mass is $M$. The number of neutron is

In the nuclear reaction
${ }_1 {H}^2+{ }_1 {H}^2 \longrightarrow{ }_2 {He}^3+{ }_0 n^1$

Mass of deuterium atom $=2.014741 \,\mathrm{amu}$, Mass of ${ }_2 {He}^3$ atom $=3.016977 \mathrm{~amu}$, and Mass of neutron $=1.008987 \mathrm{~amu}.$
The $Q$-value of the reaction will be:

The ratio of the energies of the hydrogen atom in its first to second excited state is

Assertion: Mass defect in nuclear reactions is less than $1 \%$.

Reason: In nuclear reaction, change in BE/N is generally less than $1\%$.

The radius of a nucleus with atomic mass number $\mathrm{7}$ is $\mathrm{2}\,\,\mathrm{fermi}$. Find the radius of nucleus with atomic number $\mathrm{189}$.

$F_{p p}, F_{n n}$ and $F_{n p}$ are the nuclear forces between proton -proton, neuron-neuron and neuron- proton respectively. Then relation between them is