Which of the following physical quantities has the same SI unit as the rf :xi. ng2cp+pucx;8 radioactive decay conf2cg8: ;n+xppc i.uxr stant?

  The diagram below showsojbfn22v g+lxj* iwc be7h8,8 the graph of binding energy per nucleon vs. the mass (nucleon) number of some elementsxc w, 7 jjv+ bol8gbn8e2*2fih.

Which is the most stable nucleus?

  A student uses the arrangement shown below to asc:yhz, fgrf( g-ertain the type of radiation emitted by a given sampleg(g r- z,yh:ff of radioactive material.

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 of)7wc wsb 1)snw $^4_2He$ is 28 MeV. What is its binding energy per nucleon?

  In the absence of the strong nuclear force, a large nuc1 6fnkc6mmtl3 leus would be even more unstable than a small nucleus. m1f k nc6ml6t3Which one of the following is the best explanation?

  An element X is bombarded with alpha particles and a new element a1lku6qzd; )f0n t h*-moee-uY is formed with a neutron emitted. The following equatioe -mqun6z-t dea) ol1 f*;u0khn 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 nuclear bith* h)o)m0pj -tvt xpb- 9nne(nding 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 canxsb9:v0 pnrmxv -zsd-0-wscbde / ;o: be represented 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 varpat b mvafa.6c-6-rh 1iation of the measured activity of an isotope sample with timpt. afrchva 61- -a6bme.

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 beta decay with oh 4orhx1bv t8t (4)yxa 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. Wh1 x 8x(t y4)4brtohhovat is the approximate total mass measured after 90 minutes?

  The activity of a 100% pure rq9i/w 9:n-vsn,d)x:ji dnsyradioactive sample is $10^6\,Bq$. The activity of the sample after 20% of nuclei have decayed is:

  During experiments observing beta decays, it was seen th y n *k6c3v7u2p)12)gciadtqt kgu1ejat the energy spectrum of the kk2dcvyte*u u)nga1t6g qjc127 3 ip)beta particles is continuous and momentum conservation was violated in beta decays. This provided evidence for the existence of:

  Which of the following radioactive de t7sqlztblgg5/im+ s3 sn-2f/cays can cause the production of a daughter nucleus to be a n illg2tq /s/- +ms7t3f5bszg different element than the parent nucleus?
I. α decay
II. β decay
III. γ decay

  A pure radioactive samplecoz1h )w-y5 eq of mass m has a decay constant of λ. Its activity is givwze-q5 hy)o1 cen by A. Another pure sample of the same material has a mass 2m. Consider the following statements about the sample 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 nucllq+0- i.e7j e8j y4df8y* p; nshfzxfoeon 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 ian*wcjxs(zs;5 x f3w3 n a 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. 8l e a su3m*tz5p.laj/
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 thl 4c)ic;+gc qrorium-234. The initial speed of the alpha particle is v. Whacq c;i+r4l )gct is correct about the magnitude of the thorium-234 velocity and its direction?

The plutonium isotopu9 iwz w2rl:9d6b o4zhe $^{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.