Which of the following physical quantities has the same *n(njk lpw3cw6 r9/zu0 y,henSI unit as the radioactive decln6jw nh/zey9p(*w knru ,0c 3ay constant?

  The diagram below shows the graph ofj) 5x *vi.ve+ db(nvaf binding energy per nucleon vs. the mass (nucla)n.5i+ jvvbdvf* xe(eon) number of some elements.

Which is the most stable nucleus?

  A student uses the arrangementx yiun 4qyv3d2 owlr/ nd+nkx05;z; k1 shown below to ascertain the type of radiation emitted by a given sa+kdlk5nnxzq/;no2i0r 43vdu wy;y x 1 mple 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 oea ycfqgu6:b; x/0mp)zx(-z lf $^4_2He$ is 28 MeV. What is its binding energy per nucleon?

  In the absence of the strong nuclear force, a large nucleus wo xhhf mcaq+z;(d:tsw0 a0)c7n uld be even more unstable than a small nucleus. Which onan:z) + wdhq0(afcch7 t0sm ;xe of the following is the best explanation?

  An element X is bombarded with alpha p lal69+uu0v znarticles and a new element Y is formed with a neutron emitted. The following equation can be written for the nuclear rez0nl9vlu a+u6 action.

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 statemik3 w6 c88 7eue1cp erhu*ds6rents about nuclear 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 radioactiy5g6 e*xn6yik ve element Q can 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 variation of the measureijsqf48o9p2 xp x -:omd activity of an isotope sample with time. 9x:o-q4f8jso pim2 px

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 r;vl0x.h bcv6mpraj-4 9+z nebeta decay with a half-life of 30 minutes is observed in a closed container in a lmxerp 4;n-hv r+jv0czb96a. l aboratory. The decay results in a daughter nucleus that is also a solid. What is the approximate total mass measured after 90 minutes?

  The activity of a 100% pure rad)68knyx tio- ;dx3ugs9d-kly ioactive 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 k9rk2-ol5 uaddk, h3kthat the energy spectrum of the beta particles is continuous and25,-urh kdk3o9kdk a l momentum conservation was violated in beta decays. This provided evidence for the existence of:

  Which of the following radioac8e8z oa oj:a2zla(),-ub usfm tive decays can cause the production of a daughter nus-z8:8j al oaufe(u,)mob a 2zcleus 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 igq)d la1rh*:/t0nvddecay constant of λ. Its activity is given by A. Another pure sample of the same material has a mass 2m. Considi/n vq hl*g1dd):r0ater 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 nuc652 r 0umf:d dwhdohk,f8an1 dleon 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 nuclear reactor: ia x 4-)6zwmqm
$^{235}_{92}U$+$^1_0n$→$^{144}_{56}Ba$+$^{89}_{36}Kr$+$3^1_0n$
(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 consti g 3ln ls(a4/euync))ant.
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 di ex(/z h2::vdo nnma(ecay to form thorium-234. The initial speed of the alpha particle is v. Wnmnho:av /:i(ed(2 zxhat is correct about the magnitude of the thorium-234 velocity and its direction?

The plutonium isotopergo4yb.syl h6n -i+.,4bbl oh $^{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.