IGCSEScienceEdexcelScience (Double Award) (Modular)Physics Unit 2Exam Questions8. Radioactivity & ParticlesProperties of Radiation

Properties of Radiation (Edexcel IGCSE Science (Double Award) (Modular): Physics Unit 2): Exam Questions

Exam code: 4XSD1

1 hour26 questions
Easy
Medium
Hard
1
1 mark

Carbon-14 is a radioactive isotope of carbon.

It has the symbol

The nuclide symbol for carbon-14: a capital letter C, with the number 14 written above and to the left of it, and the number 6 written below and to the left of it.

The number of nucleons in a carbon-14 nucleus is

  • 6

  • 8

  • 14

  • 20

Choose your answer

2
1 mark

Which of these is the same as an electron? 

  • Alpha particle

  • Beta particle

  • Gamma ray

  • X-ray

Choose your answer

3a
2 marks

Sodium-24 is a radioactive isotope.

What are isotopes?

How did you do?

3b
4 marks

Sodium-24 decays by emitting beta particles.

(i) Describe the nature of a beta particle.

[1]

(ii) Name a piece of equipment that can be used to detect beta particles.

[1]

(iii) Describe how a detector can be used with sheets of lead, aluminium and paper to show that a sample of sodium-24 emits beta particles.

[2]

How did you do?

4a
3 marks

Scientists use the term radiation in different ways.

Sometimes radiation means streams of particles and sometimes radiation means high frequency waves.

Draw a straight line from each description to the type of radiation it describes.

Matching exercise with two columns of boxes. The left column, headed description, has three boxes reading electromagnetic waves, particles with a negative charge, and particles with a positive charge, each with a dot on its right-hand edge. The right column, headed type of radiation, has four boxes reading alpha, beta, gamma and neutron, each with a dot on its left-hand edge. No lines have been drawn between the two columns.

How did you do?

4b
1 mark

People who work with ionising radiation need to measure the amount of radiation they are exposed to. For many years, a film badge was used to detect the radiation.

State the name of another device that can be used to detect alpha radiation.

How did you do?

5
1 mark

When carbon-14 decays it emits a beta particle.

What is a beta particle?

  • An electron

  • A neutron

  • A nucleus

  • A proton

Choose your answer

6
2 marks

The radioactive nuclei in a source emit beta radiation.

What effect does the emission of a beta particle have on a nucleus?

How did you do?

7a
2 marks

There are different types of ionising radiation.

Type of ionising radiation

Charge

Emitted by

alpha particle

unstable nuclei

beta particle

−

unstable nuclei

gamma ray

0

Complete the table to show the properties of each type.

How did you do?

7b
1 mark

A radioactive source contains strontium-90.

A strontium-90 nucleus emits a beta particle.

A nuclear decay equation. On the left is the symbol Sr, with the mass number 90 above and to the left and the atomic number 38 below and to the left. An arrow points right to the symbol Y, which has a blank dotted line above and to its left where the mass number should go and a second blank dotted line below and to its left where the atomic number should go. This is followed by a plus sign and the Greek letter beta with a superscript minus sign, carrying the mass number 0 above and to the left and the atomic number minus 1 below and to the left.

Complete the equation to show how strontium-90 decays.

How did you do?

1a
1 mark

Radon is a gas produced by some types of rocks.

Radon is a natural source of radioactivity.

What is the name for this radioactivity?

  • Chain reaction

  • Background radiation

  • Radioactive dating

  • Radiotherapy

Choose your answer

1b
1 mark

Radon-222 and radon-220 are both isotopes of radon. A nucleus of radon-222 has 86 protons.

How many protons are there in a nucleus of radon-220?

  • 86

  • less than 86

  • more than 86

  • none

Choose your answer

1c
1 mark

Radon-222 and radon-220 are both isotopes of radon. A nucleus of radon-222 has 136 neutrons.

How many neutrons are there in a nucleus of radon-220? 

  • 86

  • 134

  • 136

  • 220

Choose your answer

2a
1 mark

Which of these particles has the largest charge? 

  • Alpha particle

  • Beta particle

  • Neutron

  • Proton

Choose your answer

2b
1 mark

Which of these particles has the largest mass? 

  • Alpha particle

  • Beta particle

  • Neutron

  • Proton

Choose your answer

2c
1 mark

The maximum range of a beta particle in air is about

  • 50 mm

  • 50 cm

  • 50 m

  • 50 km

Choose your answer

2d
1 mark

When a nucleus emits a beta particle 

  • The nucleon number decreases by 1 

  • The nucleon number increases by 1 

  • The proton number decreases by 1 

  • The proton number increases by 1 

Choose your answer

3
1 mark

Which of these has a mass (nucleon) number of 4? 

  • Alpha particle

  • Beta particle

  • Gamma ray

  • X-ray

Choose your answer

4
1 mark

Which of these is the most ionising? 

  • Alpha particle

  • Beta particle

  • Gamma ray

  • X-ray

Choose your answer

5
1 mark

When an unstable nucleus emits an alpha particle, its mass (nucleon) number 

  • Increases by 1

  • Stays the same

  • Decreases by 2

  • Decreases by 4

Choose your answer

6
1 mark

Which of these describes what happens to the strontium-90 nucleus when it emits a beta particle?  

  • The number of protons stays the same 

  • The number of protons increases 

  • The number of neutrons stays the same 

  • The number of neutrons increases 

Choose your answer

7a
2 marks

A teacher uses this apparatus to demonstrate radioactivity to his students.

Photograph of laboratory apparatus for measuring radioactivity, carrying four labels. A counter unit with a digital display and control knobs stands at the back. In front of it, mounted along a horizontal rail from left to right, are a source in a small block holder, an absorber held upright in a clamp, and a detector, a cylindrical tube pointing towards the source and connected to the counter. A credit line reads Focus Investigations.

The teacher needs to take some safety precautions.

Put one tick (✓) on each row to show whether the safety precaution is needed or not. Two have been done for you.

safety precaution

needed

not needed

not touch the source with bare hands

✓

use tongs

wear gloves

✓

wear goggles

students sit at least two metres away

wear a lead apron

store source in a lead box

How did you do?

7b
3 marks

The teacher uses this method to investigate radioactivity.

  • Place the detector 10 cm from the radioactive source

  • Record the count with different absorbent materials between the source and the detector

  • Repeat the investigation using a different radioactive source

  • Also repeat the investigation without a source

The table shows his results.

Results table. The first column is headed Source used. The remaining six columns sit under one heading, Counts in 30 s for each material, and are headed 5 mm of aluminium, 5 mm of lead, 0.2 mm of paper, 5 mm of plastic, 5 mm of stone and 5 mm of wood. For barium-133 the counts are 3843, 1989, not taken, 4551, 10408 and 4557. For strontium-90 the counts are 14, 15, 42770, 182, 13 and 331. For none the counts are 15, 15, 14, 15, 14 and 15.

(i) State why the teacher keeps the distance constant between the source and the detector.

[1]

(ii) Explain why there is a reading when no source is used.

[2]

How did you do?

7c
6 marks

(i) Explain which of the materials the teacher used is the best absorber of radiation.

[3]

(ii) A student makes this conclusion.

"Stone is the worst absorber of radiation."

Evaluate this conclusion

[3]

How did you do?

8a
3 marks

The table describes the nuclei of four atoms.

A table of four nuclei. The column headings are uranium-234, uranium-235, plutonium-238 and americium-238. Under each heading is the nuclide symbol, with its nucleon number written above and to the left of the symbol and its proton number written below and to the left. Uranium-234 is shown as U with 234 above and 92 below. Uranium-235 is shown as U with 235 above and 92 below. Plutonium-238 is shown as Pu with 238 above and 94 below. Americium-238 is shown as Am with 238 above and 95 below

(i) Which two nuclei have the same number of protons?

[1]

(ii) Which two nuclei have the same number of nucleons?

[1]

(iii) Which two nuclei have the same number of neutrons?

[1]

How did you do?

8b
3 marks

All of the nuclei are unstable and have a different half-life.

(i) Explain what is meant by the term unstable.

[1]

(ii) Explain what is meant by the term half-life

[2]

How did you do?

8c
5 marks

When plutonium decays, it emits an alpha particle and a gamma ray.

(i) Complete the decay equation for plutonium-238.

[4]

An incomplete nuclear decay equation with empty boxes to be filled in. On the left is Pu, with a box containing 238 above and to the left of the symbol and a box containing 94 below and to the left. An arrow points to the right. After the arrow is the Greek letter alpha, with a box containing 4 above and to the left and an empty box below and to the left. A plus sign follows, then a bold X with an empty box above and to the left and an empty box below and to the left. Another plus sign follows, then the Greek letter gamma with an empty box above and to the left and a box containing 0 below and to the left

(ii) Use information from the table in part (a) to identify element X.

[1]

How did you do?

8d
3 marks

The nucleus of americium-238 can absorb an electron. When this happens, one of the protons in the nucleus becomes a neutron.

This equation describes the process.

An equation showing a proton absorbing an electron to form a neutron. The proton is written as p, with 1 above and to the left of the symbol and 1 below and to the left. A plus sign follows, then the electron, written as e with 0 above and to the left and minus 1 below and to the left. An arrow points to the right to the neutron, written as n with 1 above and to the left and 0 below and to the left

(i) Describe how this process affects the proton number and the nucleon number of the nucleus that absorbs the electron.

[2]

(ii) Identify the new nucleus formed by this process.

[1]

How did you do?

9
5 marks

The table shows the nature of alpha and beta particles.

Two-column table headed Particle and Nature. Row one reads alpha, helium nucleus. Row two reads beta, electron.

Explain why alpha particles and beta particles have different penetrating powers.

How did you do?

10a
2 marks

Thorium-232 and thorium-228 are radioactive isotopes of thorium and can be represented as

Th90232‎

Th90228

Describe a similarity and a difference between the nuclei of these two isotopes of thorium.

How did you do?

10b
3 marks

Both thorium-232 and thorium-228 decay by alpha emission.

(i) Describe how a nucleus changes as a result of alpha emission.

[2]

(ii) Thorium-228 also emits gamma radiation.

Describe the nature of gamma radiation.

[1]

How did you do?

11
1 mark

When an unstable nucleus emits an alpha particle, its atomic (proton) number 

  • Increases by 1

  • Stays the same

  • Decreases by 2

  • Decreases by 4

Choose your answer

12a
1 mark

lodine-131 is a radioactive isotope that emits beta particles.

The equation for this decay is

Nuclear decay equation. The symbol I has 131 above and to the left and 53 below and to the left. An arrow points right to the symbol Xe, which has A above and to the left and Z below and to the left, followed by a plus sign and the symbol e, which has 0 above and to the left and minus 1 below and to the left.

The mass (nucleon) number for Xe is

  • −1

  • 0

  • 53

  • 131

Choose your answer

12b
1 mark

The atomic (proton) number for iodine-131 is 

  • 0

  • 53

  • 78

  • 131

Choose your answer

13
1 mark

Tellurium-120 is an isotope of tellurium.

It has the symbol Te52120

The number of protons, neutrons and electrons in a neutral tellurium-120 atom is

  • p = 120

    n = 52

    e = 120

  • p = 120

    n = 68

    e = 68

  • p = 52

    n = 120

    e = 120

  • p = 52

    n = 68

    e = 52

Choose your answer

1
1 mark

A doctor uses gamma radiation to produce an image of a person's brain.

A radioactive isotope called technetium-99m is used in this process.

Technetium-99m emits gamma rays and has a short half-life.

Greyscale scan image of a human brain, shown as a square black panel centred on a white background. The scan is a horizontal slice viewed from above, with bright white bands tracing the outline of the brain and its internal structures, mid-grey tissue between them, and several darker grey patches near the centre and towards the top and bottom. No labels, scale or markings are shown.

Gamma radiation consists of

  • Electromagnetic waves

  • Negatively charged particles

  • Positively charged particles

  • Unstable atoms

Choose your answer

2
1 mark

The table describes the nuclei of four atoms.

A table with four columns headed uranium-234, uranium-235, plutonium-238 and americium-238. Below each heading is the nuclide symbol for that atom, with the mass number above and to the left of the element symbol and the atomic number below and to the left. The uranium-234 column shows 234 above, U, and 92 below. The uranium-235 column shows 235 above, U, and 92 below. The plutonium-238 column shows 238 above, Pu, and 94 below. The americium-238 column shows 238 above, Am, and 95 below.

Atoms contain electrons.

Which nucleus needs the largest number of electrons to form a neutral atom?

  • Uranium-234

  • Uranium-235

  • Plutonium-238

  • Americium-238

Choose your answer

3
1 mark

Compared to a beta particle, an alpha particle 

  • Causes less ionisation 

  • Has less charge 

  • Has less mass 

  • Has less penetrating power

Choose your answer

4a
3 marks

The grid shows the number of neutrons and the number of protons in some isotopes formed during successive radioactive decays.

A grid with number of protons on the horizontal axis, labelled 80, 82, 84 and 86, and number of neutrons on the vertical axis, which is ruled with gridlines but carries no numbers. Five isotopes are marked at grid intersections and joined by arrows showing successive decays. Polonium-214 sits at 84 protons on the top gridline. An arrow runs down and to the left from it to lead-210 at 82 protons, two rows lower. An arrow runs down and to the right to bismuth-210 at 83 protons, one row lower. An arrow runs down and to the right to polonium-210 at 84 protons, one row lower. An arrow runs down and to the left to lead-206 at 82 protons, two rows lower. A key to the right states that an open circle is an unstable isotope and a filled circle is a stable isotope. Lead-206 is the only filled circle; the other four isotopes are open circles.

(i) What are isotopes?

[2]

(ii) Why are some isotopes described as stable?

[1]

How did you do?

4b
4 marks

(i) Use the grid in part (a) to calculate the number of neutrons in a Po210 nucleus.

[1]

(ii) Describe what happens to the number of protons and the number of neutrons when a nucleus of Pb210 decays to form Bi210.

[2]

(iii) State the type of decay that occurs when Pb210 decays to form Bi210.

[1]

How did you do?

4c
2 marks

Explain why the mass (nucleon) number and the atomic (proton) number do not change when a gamma ray is emitted from a nucleus.

How did you do?

5
4 marks

Scientists use deflection in an electric field to help distinguish between different types of radiation.

The diagram shows a beam containing several types of radiation. This beam travels in a vacuum between two charged plates.

Some of the radiation is deflected upwards, some is deflected downwards, and some are not deflected at all.

Diagram of a beam of radiation travelling from left to right through a vacuum between two horizontal charged plates. The upper plate is labelled negatively charged plate and has a row of minus signs along its underside. The lower plate is labelled positively charged plate and has a row of plus signs along its upper side. After passing between the plates the beam fans out into three dashed paths: one curving upwards towards the negatively charged plate, one continuing straight ahead undeflected, and one curving downwards towards the positively charged plate. The region between the upper and lower paths is shaded grey.

Put one tick in each row to show the correct deflection for each type of radiation.

One has been done for you.

Type of radiation

Deflected upwards

Deflected downwards

Not deflected

alpha

✓

beta

gamma

neutrons

protons

How did you do?

6a
2 marks

Alpha particles, beta particles and gamma rays have different properties.

Complete the table by ticking the correct type of radiation for each property. The first one has been done for you.

Property

Type of radiation

alpha particles

beta particles

gamma rays

most ionising

✓

largest mass

most penetrating

highest speed

negatively charged

How did you do?

6b
3 marks

The symbol for the structure of an alpha particle is

The symbol for an alpha particle: the Greek letter alpha, with the mass number 4 written above and to the left of it, and the atomic number 2 written below and to the left of it.

(i) State the number of neutrons and the number of protons in an alpha particle.

[2]

(ii) Suggest why alpha radiation is more ionising than beta or gamma radiation.

[1]

How did you do?