Which of the following physical quantities has the same SI unit as the radioactsdu7msf99+; 4rafeb npulqg0- *u-l )5d mfqmive +umpg0fu l9lfdsmf*-muab- q57)dns49qe;rdecay constant?

  The diagram below shows the graph of binding energy per nucleo.j6t 0uh y3(hze/y nbwn vs. the mass (nucleon) number of bn(z 3u 0ye.whhtjy6/ some elements.

Which is the most stable nucleus?

  A student uses the arrange/x eu88o,g,as2ynq inment shown below to ascertain the type of radiation emitted by a given sample of radioactive m/gu,qn2e 8i a8,nso xyaterial.

The SI unit of radioactive decay constant is $s^{−1}$, which is the same as that of frequency.When the sheet of paper is in the position shown, a count rate of 720 Bq is recorded. When she lowers the thick sheet of paper so as to obstruct the direct path between the source and the detector, the count rate drops to 18 Bq. Which of the following is the most likely explanation for the data collected?

  The binding energy o99 ibj,zs0w0 fuu(cmyiwk6s 4f $^4_2He$ is 28 MeV. What is its binding energy per nucleon?

  In the absence of the strong nuclear force, a large nucleus would bgw aw.:d m7:;xntz1h qd+0arfe even more unstable than a small nucleus. Which one of the following is the best fqw arwn.x 07 +tmz;:1d ahdg:explanation?

  An element X is bombuq(y8h+c i0 e eiq*re+arded with alpha particles and a new element Y is formed with a neutron emitted. Th8 eqh ci0e+iey+(q*rue following equation can be written for the nuclear reaction.

The atomic numbers of X and Y are A and B respectively. Which of the following is correct for A and B?

  Consider the following statements about nucleari )2 upe/(1dxql2vta k binding energy:
The nuclear binding energy is:
I. proportional to the mass defect from nucleus formation.
II. the energy released when a nucleus is formed from its nucleons.
III. the energy required to remove a proton from the nucleus.
Which of the statements are correct?

  A nuclide of a radioactive element Q can be ryw*kr :biy:/7tlo +,hoah ) yrepresented as $^{234}_{90}Q$. The nuclide undergoes two negative beta decays and one alpha decay. Which of the following configurations correctly represents the daughter nuclide R?

The graph shows the variation of the measured activity of an iswzvr*h dl4e k 6l0p6-zotope sample with timez4 v6kp hlwze6dl0*r- .

1.State what is meant by activity.
2.Explain why the activity graph doesn’t approach zero as time increases.
3.The activity graph is corrected so as to reach zero as time increases as shown below.

(1)Determine the half-life of the sample.
(2)The initial mass of this sample was 248 g. Determine the time that would elapse before 31 g of the sample remained.

  A 1.20 kg sample of a radioactive isotope decaying via bc9n*:ai gciq0eta decay with a half-life of 30 minutes is observed in a closed container in a laboratory. The decay results in a daughter nucleus that is also a solid. What is the ap:ia* cngi cq09proximate total mass measured after 90 minutes?

  The activity of a 100 kzf(zg 03chg2 7q5g ih6z2 a,.ocbnfz% pure radioactive sample is $10^6\,Bq$. The activity of the sample after 20% of nuclei have decayed is:

  During experiments observing beta decays, it wasn:3c xgxz76fo5ipz 9a seen that the energy spectrum of the beta particles is continuous and momentum conservation was violated in beta decays. This provided evidence for the existence i3no69gza f:pcxx7 5z of:

  Which of the following raz1wk s0c);dkv 4p f/epbl9i)a dioactive decays can cause the production of a daughter nf w;b)k0czvks le1i)p/49d paucleus to be a different element than the parent nucleus?
I. α decay
II. β decay
III. γ decay

  A pure radioactive sample of mass m has a decay constant of λ. Its activity is gs6* ;gqp+ wzsjf:klx/iven by A. Another pure sample of the same material has a mass 2m. Consider the following statements about the sample+zwglp*:k;q6xssjf / of mass 2m after an interval of two half lives.
I. The decay constant is $\frac{λ}{2}$​.
II. The activity is $\frac{A}{2}$​.
III. The mass of decayed nucleons in the sample is $\frac{m}{2}$​.
Which of the statements is/are correct?

  The binding energy per t9uteevd xba ( n+a+-4b:e1) dpwo1 osnucleon of a $^A_ZX$ nucleus is E. What is the mass defect for the formation of X from its constituent nucleons?

1.The following reaction takes place in a qwzlrd6 gb,2(nuclear reactor:
$^{235}_{92}U$+$^1_0n$→$^{144}_{56}Ba$+$^{89}_{36}Kr$+$3^1_0n$
(1)Differentiate between fission and fusion reactions.
(2)Determine whether this reaction is a nuclear fission or nuclear fusion.
2.The following data is given for this reaction:
The binding energy per nucleon of $235^​U$ = 7.59 MeV
The binding energy per nucleon of $144​^Ba$ = 8.27 MeV
The binding energy per nucleon of $89^​Kr$ = 8.62 MeV
Calculate the energy released from this reaction.

  A nucleus $A^​$X has a mass defect of N unified atomic mass units, Nu. What is the correct expression for its binding energy per nucleon?

  1.Uranium-235 $(^{235}_{92}​U)$ has a nuclear mass of 235.044 u.
(1)State what is meant by mass defect.
(2)Calculate the mass defect of uranium-235. $δ$ =    $u$
2.(1)Calculate the binding energy per nucleon of uranium-235. $binding energy per nucleon$ =    $MeV$
(2)On the axes given, sketch the variation of the binding energy per nucleon with the nucleon number. Label the position of uranium-235. There is no need to add numbers to the axes.

3.Uranium-235 ( $^{235}_{92}​U$) decays into thorium-231 ( $^{231}_{90}Th$).
Determine which nuclide has a higher binding energy per nucleon. Use the graph to justify your answer.

1.Define decay constant. edyr5+;mvpyel6 5t;w /jaw6r
2.Mushrooms contain a radioactive element called caesium-137, $^{137}_P{55}$​Cs . The element has a half-life of 30$yr$ and a sample of living mushrooms has a constant decay rate of 2000 2000Bq for every kg of mass. A sample of 50g is extracted from a dried mushroom and the activity is measured as 0.80Bq.
(1)Caesium-137 decays to barium-137, $^{137}_{56}Ba$, by beta emission. Complete the nuclear reaction equation of this decay, showing both particles emitted in the decay.
$^{137}_P{55}$​Cs→ ______ +$^{137}_{56}Ba$ + ______
(2)Show that the decay constant of caesium-137 is about 0.023 $yr^{−1}$.
(3)Given that the amount of caesium in the mushroom stops being replenished once the mushroom is no longer living, determine the age of the dried mushroom.
3.Some other radioactive substances have half-lives of thousands of years. Outline the method used for determining the half-life of these kinds of substances.

  A stationary nucleus of uranium-238 undergoes alpha decay to form thorium-234. Tfld(m ; prv8m(he initial speed of the alpha particle is v. What is corrlr pm(d8;fv(mect about the magnitude of the thorium-234 velocity and its direction?

The plutonium isotope 3 ( f rym*p)obo3cc8uv$^{238}_{94}​Pu undergoes alpha decay.

1.Define isotope.
2.Rewrite this decay equation, filling in any missing information.
3.Plutonium undergoes a decay series. The graph below shows a part of this decay series.

(1)One type of decay cannot be represented on this diagram. Outline this type of decay and justify your answer.
(2)State the type of decay of $^{230}_{90}​Th$ that is represented on the diagram above. Justify your answer.
(3)Isotope X undergoes an alpha decay followed by a beta minus decay to produce isotope Y. Label the position of isotope Y on the diagram.
4.Compare the penetrating powers of alpha, beta and gamma radiation.