a half the time taken for half the substance to decay b ... · pdf filea nuclide d an x-ray 38...

38 Which statement explains the meaning of the half-life of a radioactive substance?

A half the time taken for half the substance to decay

B half the time taken for the substance to decay completely

C the time taken for half the substance to decay

D the time taken for the substance to decay completely

39 The diagram shows the paths of three different types of radiation, X, Y and Z.

X

Y

Z2 mm ofplastic

10 mmof aluminium

lead

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY

92

Which row in the table correctly identifies X, Y and Z?

X Y Z

A

B

C

D

α-particles

β-particles

β-particles

γ-rays

β-particles

α-particles

γ-rays

α-particles

γ-rays

γ-rays

α-particles

β-particles

40 How many neutrons and how many protons are contained in a nucleus of 238 U?

neutrons protons

A

B

C

D

92

146

146

238

146

92

238

92

38 Which type of radiation has the greatest ionising effect?

A α-

particl

es B

β-

particl

es C

γ-rays

D all have the sameionising effect

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY39 A powder contains 400 mg of a radioactive material that emits α-particles.

The half-life of the material is5 days.

What mass of that material remains after10 days?

A 0 mg B 40 mg C 100 mg D200 mg

40 In the symbol below, A is the nucleon number and Z is the proton number.

A

XZ

What is represented by thesymbol?

A anelectron

B a

neutron C

a nuclide D

an X-ray

38 A radioactive nucleus emits a β-particle.

β-particle

nucleus

What happens to the proton number (atomic number) of the nucleus?

A It stays the same.

B It increases by 1.

C It decreases by 2.

D It decreases by 4.

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY39 The diagram shows the paths of three different types of radiation, X, Y and Z.

X

Y

Z2 mm ofplastic

10 mm ofaluminium

50 mmof lead


X Y Z

A

B

C

D

α-particles

β-particles

β-particles

γ-rays

β-particles

α-particles

γ-rays

α-particles

γ-rays

γ-rays

α-particles

β-particles

40 Which diagram could represent the structure of a neutral atom?A B C

– – –

+ + + ++ Dkey

– neutron+ proton

+ ++ – electron

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

2020MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 The table shows the results of an experiment to find the half-life of a radioactive substance.

time / scount rate from substance

counts / second

0

60

120

180

240

150

120

95

75

60

What is the half-life of the substance?

A 60 seconds

B 120 seconds

C 180 seconds

D 240 seconds

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

2121MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY39 The diagram shows a box used for storing radioactive sources.

Which material is best for lining the box to prevent the escape of most radioactive emissions?

A aluminium

B copper

C lead

D steel

38 The diagram shows an experiment to monitor the radiation from a radioactive gas. The counterreadings are corrected for background radiation.

000.0

radioactive gas

The table shows how the counter reading varies with time.

counter

time / seconds 0 20 40 60 80 100 120 140 160 180

counter reading /counts per minute

140 105 82 61 44 36 27 20 15 10

What is the half-life of the gas?

A between 20 and 40 seconds

B between 40 and 60 seconds

C between 60 and 140 seconds

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

2222MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY

92

D between 140 and 180 seconds

39 Which material is commonly used as a lining for a box for storing radioactive samples?

A aluminium

B copper

C lead

D uranium

40 A uranium 238 U nucleus emits an α-particle.

What are the new nucleon and proton numbers?

nucleon number proton number

A

B

C

D

238

236

234

234

88

90

92

90

38 What is a β-particle and from which part of a radioactive atom is it emitted?

β-particle emitted from

A

B

C

D

electron

electron

helium nucleus

helium nucleus

nucleus

outer orbits

nucleus

outer orbits

39 A sample of radioactive uranium has mass 1 g. Another sample of the same material hasmass 2 g.

Which property is the same for both samples?

A the amount of radiation emitted per second

B the half-life

C the number of uranium atoms

D the volume

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

1818MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY17

40 A particular nuclide has the symbol 37 Cl .

What is true for atoms of this nuclide?

A There are 17 nucleons in the nucleus.

B There are 17 protons in the nucleus.

C There are 37 electrons in the nucleus.

D There are 37 neutrons in the nucleus.

38 What are the most penetrating and the least penetrating types of radiation?

most penetrating least penetrating

A

B

C

D

α-particles

β-particles

γ-rays

γ-rays

β-particles

α-particles

α-particles

β-particles

39 The half-life of a radioactive substance is 5 hours. A sample is tested and found to contain 0.48 gof the substance.

How much of the substance was present in the sample 20 hours before the sample was tested?

A 0.03 g B 0.12 g C 1.92 g D 7.68 g

40 The data below relates to the nucleus of a particular neutral atom of nitrogen. proton

number Z = 7

nucleon number A = 17

Which row represents the correct number of neutrons and electrons in this atom?

number of neutrons number of electrons

A

B

C

D

10

10

17

17

7

10

7

10

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12


nuclide 1 nuclide 2 nuclide 3

1H 2 H 3 H

37 Which line in the table describes the nature of an α-particle and of a γ-ray?

α-particle γ-ray

A

B

C

D

helium nucleus

helium nucleus

proton

proton

electromagnetic radiation

electron

electromagnetic radiation

electron

38 The count rates of four radioactive sources were measured at the same time on threeconsecutive days.

Which source has a half-life of two days?

Monday Tuesday Wednesday

A

B

C

D

100

200

300

400

50

140

300

200

25

100

300

100

39 Which statement is true of all neutral atoms?

A The number of electrons equals the number of nucleons.

B The number of neutrons equals the number of protons.

C The number of nucleons equals the number of neutrons.

D The number of protons equals the number of electrons.

40 There are three nuclides of hydrogen.

1 1 1

Which of these nuclides have the same number of protons in their nuclei?

A 1 and 2 only

B 2 and 3 only

C all of them

D none of them

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12


37 Charged particles are emitted from the cathode of an oscilloscope.

What is the name and the charge of these particles?

name of particles charge of particles

A

B

C

D

electrons

electrons

protons

protons

negative

positive

negative

positive

2121

© UCLES 2005 0625/01/O/N/050625/01/O/N/05

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 A radioactive source emits radiation that can pass through a sheet of paper but not through thick

aluminium.paper

(all the radiationpasses through)

thick aluminium(none of the radiation

passes through)

radiation

What does this show about the radiation?

A It is α-particles.

B It is β-particles.

C It is γ-rays.

D It is a mixture of α-particles and γ-rays.

39 An unstable nucleus has 145 neutrons and 92 protons. It emits a β-particle.

How many neutrons and protons does the nucleus have after emitting the β-particle?

neutrons protons

A

B

C

D

144

144

145

145

92

93

91

93

40 Which particles are found in the nucleus of an atom?

A neutrons and protons only

B neutrons only

C protons and electrons only

D protons, electrons and neutrons

2222

© UCLES 2005 0625/01/O/N/050625/01/O/N/05

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 A sheet of paper is placed between a radioactive source and a detector.

radioactivesource sheet of paper

detector

Which types of radiation can pass through the paper?

A α-particles and β-particles only

B α-particles and γ-rays only

C β-particles and γ-rays only

D α-particles, β-particles and γ-rays

39 A sample of radioactive isotope is decaying.

The nuclei of which atoms will decay first?

A impossible to know, because radioactive decay is random

B impossible to know, unless the age of the material is known

C atoms near the centre, because they are surrounded by more atoms

D atoms near the surface, because the radiation can escape more easily

© UCLES 2005 0625/01/O/N/050625/01/O/N/05

1818MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY40 An atom of the element lithium has a nucleon number of 7 and a proton number of 3.

Which diagram represents a neutral atom of lithium?

A B

– –

n + ++ + ++ n n key

n = a neutron– –+ = a proton

–– = an electron

C D (not to scale)

––

+ n +n n n+

–– –

+ n +n n n+

– –– –

–

© UCLES 2005 0625/01/O/N/050625/01/O/N/05

1519MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY 38 The diagram shows five atoms in a radioactive substance. The atoms each give out an α-

particle.

atom 1

1st particle

atom 5

atom

2

atom 4

atom

3

2nd particle

Atom 1 is the first to give out a particle. Atom 3 is the second to give out a

particle. Which atom will give out the next particle?

A atom 2

B atom 4

C atom 5

D impossible to tell

© UCLES 2005 0625/01/O/N/050625/01/O/N/05

2020MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY 39 A Geiger counter detects radiation from radioactive sources.

A radioactive source is inside a thick aluminium container as shown.

radioactive source

o 2

m Geiger counter

thick aluminium container

Which type of radiation from this source is beingdetected?

A α-

particl

es B

β-

particl

es C

γ-rays

D radio waves

© UCLES 2005 0625/01/O/N/050625/01/O/N/05

2121MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 The diagram shows a radioactive source, a thick aluminium sheet and a radiation detector.

radioactivesource

thick aluminiumsheet

radiation detector

The radiation detector shows a reading greater than the background reading.

Which type of radiation is being emitted by the source and detected by the detector?

A α-radiation

B β-radiation

C γ-radiation

D infra-red radiation

2222

© UCLES 2014 0625/11/O/N/14© UCLES 2014 0625/11/O/N/14


Q

39 The count rate from a radioactive isotope is recorded every hour. The count rate is corrected forbackground radiation.

The table shows the readings.

time / hours 0 1 2 3 4 5

corrected count rate

counts /s800 620 480 370 290 220

What estimate of the half-life of the isotope can be obtained from the readings in the table?

A between 1 and 2 hours

B between 2 and 3 hours

C between 3 and 4 hours

D between 4 and 5 hours

40 A nuclide is represented by the symbol P X.

How many neutrons are in one nucleus of the nuclide?

A P B Q C P + Q D P – Q

© UCLES 2014 0625/11/O/N/14© UCLES 2014 0625/11/O/N/14

1818MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 A radioactive element has a half-life of 70 s.

The number of emissions per second, N, of a sample of the element is measured at a certaintime.

What was the number of emissions per second 70 s earlier?

A 0 B N / 2 C N D 2N

39 S is a radioactive source emitting α-particles, β-particles and γ-rays. A detector is placed 5 cmaway from S. A thin sheet of paper is placed as shown in the diagram.

thin sheet of paper

S detector

5 cm

Which radiations can be detected?

A α-particles and β-particles only

B α-particles and γ-rays only

C β-particles and γ-rays only

D α-particles, β-particles and γ-rays

© UCLES 2014 0625/11/O/N/14© UCLES 2014 0625/11/O/N/14

1919MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY40 In the atomic model, an atom consists of a central mass, orbited by much smaller particles.

centralmass

orbitingparticles

What is the name of the central mass and of the orbiting particles?

central mass orbiting particles

A

B

C

D

neutron

neutron

nucleus

nucleus

α-particles

electrons

α-particles

electrons

38 Which row describes the properties of α-particles?

ionizingeffect

radiation stoppedby aluminium?

A

B

C

D

large

large

small

small

no

yes

no

yes

39 A radioactive substance has a half-life of 2 weeks. At the beginning of aninvestigation the substance emits 3000 β-particles per minute.

How many β-particles will it emit per minute after 6 weeks?

A 0 B 375 C 500 D 1500

© UCLES 2014 0625/11/O/N/14© UCLES 2014 0625/11/O/N/14

2020MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY22640 The nuclide notation for radium-226 is 88 Ra .

How many electrons orbit the nucleus of a neutral atom of radium-226?

A 0 B 88 C 138 D 226

38 A radioactive nucleus contains 138 neutrons. The nucleus emits an α-particle.

How many neutrons are in the nucleus after it has emitted the α-particle?

A 134 B 136 C 138 D 139

2121

© UCLES 2009 0625/11/M/J/09


7

39 The graph shows the decay curve for one particular radioactive nuclide.

count ratecounts /min

2500

2000

1500

1000

500

00 1 2 3 4 5

time / days

What is the half-life of this nuclide?

A 1.0 day B 1.5 days C 2.0 days D 2.5 days

40 16 N is the symbol for a particular nuclide of nitrogen.

How many nucleons does this nuclide contain?

A 7 B 9 C 16 D 23

© UCLES 2009 0625/11/M/J/09


Ra

39 A student investigates how the radiation from a radioactive source changes with time.

The table shows the results from the detector used by the student.

time /minutes

count rate /counts per minute

0

2.0

4.0

6.0

8.0

340

180

100

60

40

The experiment is repeated by many other students, who also measure the count rate every twominutes.

The half-life of the source is known to be exactly 2.0 minutes.

Why is the measured count rate always greater than half the previous value?

A Radioactive emissions occur randomly with time.

B The detector used is very close to the source.

C There is background radiation present.

D The radioactive source is decaying.

22640 The nuclide notation for radium-226 is 88 .

How many electrons orbit the nucleus of a neutral atom of radium-226?

A 0 B 88 C 138 D 226

© UCLES 2009 0625/11/M/J/09

2323MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 Which row gives the properties of the radiation from radioactive materials?

most penetrating radiation most highly ionising radiation

A

B

C

D

α

β

γ

γ

β

γ

α

γ

© UCLES 2009 0625/11/M/J/09


C

39 In a laboratory, a detector of ionising radiation records an average background count rate of8 counts per second.

detector

counts / s

A radioactive source is now placed close to the detector. The count rate on the detector rises to200 counts per second.

detector

counts / s

radioactivesource

What is the count rate due to radiation from the radioactive source?

A 25 counts / s

B 192 counts / s

C 200 counts / s

D 208 counts / s

1440 6 is a nuclide of carbon.

What is the composition of one nucleus of this nuclide?

neutrons protons

A

B

C

D

6

6

8

14

8

14

6

6

1818

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 A radioactive nucleus emits a β-particle.

β-particle

nucleus

What happens to the proton number (atomic number) of the nucleus?

A It stays the same.

B It increases by 1.

C It decreases by 2.

D It decreases by 4.

39 The diagram shows the paths of three different types of radiation, X, Y and Z.

X

Y

Z2 mm ofplastic

10 mm ofaluminium

50 mmof lead


X Y Z

A

B

C

D

α-particles

β-particles

β-particles

γ-rays

β-particles

α-particles

γ-rays

α-particles

γ-rays

γ-rays

α-particles

β-particles

1919

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY38 A scientist needs to use a source of γ-rays as safely as possible.

Which action will not reduce the amount of radiation that reaches the scientist?

A keeping the distance between the source and the scientist as large as possible

B keeping the temperature of the source as low as possible

C keeping the time for which the scientist uses the source as small as possible

D placing a lead screen between the scientist and the source

2020

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12


12

39 The graph shows the activity of a radioactive source over a period of time.

activity/ counts persecond

2000

1500

1000

500

00 1 2 3

time / hour

What is the half-life of the source?

A 1 hour B 1 hour C 1 1 hours D 3 hours2 2

40 A nuclide of substance X has the symbol 26 X .

How many electrons are there in a neutral atom of substance X?

A 12 B 14 C 26 D 38

2121

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY3737 How many neutrons are in a nucleus of the nuclide 17 Cl ?

A 17 B 20 C 37 D 54

38 A certain element has several isotopes.

Which statement about these isotopes is correct?

A They must have different numbers of electrons orbiting their nuclei.

B They must have the same number of neutrons in their nuclei. C They must have the same number of nucleons in their

nuclei. D They must have the same number of protons in their

nuclei.

39 A radioactive nucleus emits either an α-particle or a β-particle.

What are the products of these two types of radioactive emission?

product after α-emission product after β-emission

A

B

C

D

a nucleus of a different element


a nucleus of the same element






2222

© UCLES 2012 0625/11/M/J/12© UCLES 2012 0625/11/M/J/12

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY40 A reading is taken every 10 minutes of the number of emissions per second from a radioactive

source. The table shows the readings.

time / minnumber ofemissions

per second

0

10

20

30

40

50

60

800

560

400

280

200

140

100

What is the half-life of the source?

A 10 min B 20 min C 40 min D 60 min

38 Which row shows the relative ionising effects and penetrating abilities of α-particles andβ-particles?

ionising effect penetrating ability

A

B

C

D

α greater than β

α greater than β

α less than β

α less than β

α greater than β

α less than β

α greater than β

α less than β

2323

© UCLES 2011 0625/11/M/J/11© UCLES 2011 0625/11/M/J/11

MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY39 A powder contains 400 mg of a radioactive material that emits α-particles.

The half-life of the material is 5 days.

What mass of that material remains after 10 days?

A 0 mg B 40 mg C 100 mg D 200 mg

40 An atom of the element lithium has a nucleon number of 7 and a proton number of 3.

Which diagram represents a neutral atom of lithium?

A B

– –

n + ++ + ++ n n key

n = a neutron– –

+ = a proton–

– = an electron

C D (not to scale)

––

+ n +n n n+

–– –

+ n +n n n+

– –– –

–

© UCLES 2011 0625/11/M/J/11© UCLES 2011 0625/11/M/J/11

21MS.RAJA ELGADY/www.rajaelgadyigcse.com/RADIOACTIVITY39 The graph shows how the count rate on a detector due to a radioactive source changes with time.

count rate4800

counts per minute

2400

00 1 2 3 4 5

time / hours

What is the count rate at 5.0 hours?

A 960 counts per minute

B 600 counts per minute

C 150 counts per minute

D 0 counts per minute

40 The diagram represents a carbon atom.

– –– – key

neutron+ + +

+ + –+

+

protonelectron

–

–

What is the nucleon number (mass number) for this atom?

A 6 B 8 C 14 D 20

a half the time taken for half the substance to decay b ... · pdf filea nuclide d an x-ray 38...

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