Question 1

When α-particles are fired at a thin metal foil, most of the particles pass straight through but a few are deflected by a large angle.

Which change would increase the proportion of α-particles deflected by a large angle?

  A  

using α-particles with greater kinetic energy

  B  

using a foil made of a metal with fewer protons in its nuclei

  C  

using a double thickness foil

  D  

using an alpha source with a higher activity

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Question 2

A radioactive nucleus emits a β− particle then an α particle and finally another β− particle. The final nuclide is

  A  

an isotope of the original element

  B  

the same element with a different proton number

  C  

a new element of higher proton number


  D  

a new element of lower nucleon number


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Question 3

The diagram shows an area of 0.10 m2 normal to a line connecting it to a point source of

gamma radiation. The source emits photons uniformly in all directions.

The area and the source are separated by a distance of 2.0 m.

The source emits 5,000 gamma photons per second.

How many photons pass through the area every second?

  A  

500

  B  

250

  C  

10

  D  

2.5

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Question 4

When a small radioactive source is placed in a cloud chamber, straight tracks about 4 cm long are observed. The same source is placed 10 cm from a Geiger tube and a count rate is detected. When a sheet of aluminium 5 mm thick is placed between the source and the Geiger tube the count rate falls to the background count rate.

Which types of radiation are emitted by the source?

  A  

α, β and γ

  B  

β and γ

  C  

α and γ

  D  

α and β


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Question 5

The first artificial radioactive substance was made by bombarding aluminium, with alpha particles. This produced an unstable isotope of phosphorus.

1327​Al
1530​P

What was the by-product of this reaction?

  A  

an α-particle

  B  

a β-particle

  C  

a γ-ray

  D  

a neutron

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Question 6

Which statement about nuclei is correct?

  A  

different isotopic nuclei have different proton numbers

  B  

for some nuclei, the nucleon number can be less than the proton number

  C  

in some nuclear processes, mass-energy is not conserved

  D  

nucleon numbers of nuclei are unchanged by the emission of β-particles

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Question 7

Which statement about alpha, beta and gamma radiation is correct?

  A  

alpha radiation has the greatest ionising power

  B  

beta radiation has the greatest ionising power

  C  

gamma radiation has the greatest ionising power

  D  

alpha, beta and gamma radiation have nearly equal ionising powers

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Question 8

It was once thought that the mass of an atom is spread uniformly through the volume of the atom.

When α-particles are directed at a piece of gold foil, the results led scientists to believe instead that nearly all the mass of the gold atom is concentrated at a point inside the atom.

Which effect is possible only if nearly all the mass of the gold atom is concentrated at a point?

  A  

a few α-particles bounce back


  B  

most α-particles are only slightly deflected

  C  

some α-particles pass through without any deflection

  D  

some α-particles are absorbed


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Question 9

A beam of α-particles collides with a lead sheet. Each α-particle in the beam has a mass of 6.6 × 10–27 kg and a speed of 1.5 × 107m s–1.

5.0 × 104 α-particles per second collide with an area of 1.0 cm2 of lead. Almost all of the α-particles are absorbed by the lead so that they have zero speed after collision.

What is an estimate of the average pressure exerted on the lead by the α-particles?

  A  

5.0 × 10–15 Pa

  B  

5.0 × 10–13 Pa

  C  

5.0 × 10–11 Pa

  D  

5.0 × 10–9 Pa

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