A ²³⁵₉₂U nucleus decays by the emission of an alpha-particles.

What are the protons number and nucleon number of the resulting nucleus?

1.   ?    proton number: 90: nucleon number: 231
2.   ?    proton number: 90: nucleon number: 235
3.   ?    proton number: 91: nucleon number: 231
4.   ?    proton number: 93: nucleon number: 235

What is a beta-particles?

1.   ?    a helium nucleus
2.   ?    an electron
3.   ?    a neutrons
4.   ?    a protons

A radioactive source has a half-life of 5 minutes. A detector connected to a ratemeter records a rate of 80 counts per seconds.

Which rate does it record after 10 minutes?

1.   ?    0 counts per second
2.   ?    20 counts per second
3.   ?    40 counts per second
4.   ?    160 counts per second

A radioactive nucleus emits a beta-particle.

What is the change in this nucleon (mass) number?

1.   ?    It decreases by 2.
2.   ?    It decreases by 1.
3.   ?    It does not change.
4.   ?    It increases by 1.

Which statement is correct for gamma radiation?

1.   ?    It can be stopped by a paper.
2.   ?    It can pass through thin aluminium.
3.   ?    It is deflected by a magnetic field.
4.   ?    It is positively charged.

After a period of 12 days, a radioactive substance emits alpha-particles at only one-eighth of its original rate.

What is the half-life of this substance?

1.   ?    1.5 days
2.   ?    4 days
3.   ?    6 days
4.   ?    8 days

A factory buys 100 g of a radioaactive chemical, with a half-life of 5 years, which decays to a stable compound.

How much of the chemical will still be radioactive in 10 years' time?

1.   ?    25 g
2.   ?    50 g
3.   ?    75 g
4.   ?    100 g

Radon decays to polonium by emission of alpha-particles, as shown by the equation:

1.   ?    x: 214; y: 82
2.   ?    x: 216; y: 80
3.   ?    x: 220; y: 88
4.   ?    x: 222; y: 86

A nucleon is represented by ²³⁰₉₁Z. It emits one alpha-particle and then one beta-particle.

What is the resulting nucleus?

1.   ?    ²²⁶₈₈X
2.   ?    ²²⁶₈₉X
3.   ?    ²²⁶₉₀X
4.   ?    ²³⁰₈₉X

The graph shows how the mass of a certain radioactive substance changes as it decays.

1.   ?    15 g
2.   ?    10 g
3.   ?    5 g
4.   ?    2.5 g

The radiation from a radioactive source passes through a sheet of solid material before reaching a detector.

1.   ?    beta particles only
2.   ?    alpha particles and beta particles
3.   ?    alpha particles and gamma rays
4.   ?    beta particles and gamma rays

A nucleus contains 90 protons and 144 neutrons.

Which symbol represents this nucleus?

1.   ?    ⁹⁰₅₄X
2.   ?    ¹⁴⁴₅₄X
3.   ?    ¹⁴⁴₉₀X
4.   ?    ²³⁴₉₀X

The half-life of a given radioactive isotope is 10 years.

What is the mass of this isotope remaining undecayed after 20 years if the original mass was 12 g?

1.   ?    0.0 g
2.   ?    0.6 g
3.   ?    1.2 g
4.   ?    3.0 g

A radioactive source is placed close to a lead barrier.
A detector on the other side of the barrier registers a high count.

What is reaching the detector from the source?

1.   ?    alpha particles only
2.   ?    beta particles only
3.   ?    gamma rays only
4.   ?    alpha particles only and beta particles only

The half-life of isotope X is four days and its initial mass is 32 mg.

What mass of the isotope X will remain after twelve days?

1.   ?    4 mg
2.   ?    8 mg
3.   ?    12 mg
4.   ?    16 mg

Alpha particles, beta particles and gamma rays all produce ionising effects.

Which of the following shows the correct order (least ionising to most ionising) ?

1.   ?    alpha particles, beta particles, gamma rays
2.   ?    alpha particles, gamma rays, beta particles
3.   ?    beta particles, alpha particles, gamma rays
4.   ?    gamma rays, beta particles, alpha particles

Which of the following has the same properties as a beta particle?

1.   ?    an atom
2.   ?    an electron
3.   ?    a helium nucleus
4.   ?    a neutron

A radioactive isotope has a half-life of 2 minutes.

Which of the following can be deduced from this statement?

1.   ?    After 4 minutes, none of the isotope remains.
2.   ?    After 4 minutes, 1/4 of the isotope remains.
3.   ?    After 1 minute, 1/4 of the isotope has decayed.
4.   ?    After 1/2 minute, 1/4 of the isotope remains.

Which material is best for making a box for the safe storage of a radioactive substance?

1.   ?    Aluminium
2.   ?    Glass
3.   ?    Graphite
4.   ?    Lead

When a radioactive atom decays by a particle emission, its nucleus loses ...................

1.   ?    1 electron only
2.   ?    1 proton only
3.   ?    1 proton and 1 electron
4.   ?    2 protons and 2 neutrons

Three different radioactive sources gave the following track patterns in a cloud chamber.

1.   ?    alpha particles, beta particles, gamma rays
2.   ?    gamma rays, beta particles, alpha particles
3.   ?    beta particles, alpha particles, gamma rays
4.   ?    alpha particles, gamma rays, beta particles

The diagram below shows the emission of alpha, beta and gamma radiations, from a source S within a lead block.
There is a strong magnetic field present.

1.   ?    X: alpha; Y: beta; Z: gamma
2.   ?    X: gamma; Y: beta; Z: alpha
3.   ?    X: beta; Y: alpha; Z: gamma
4.   ?    X: alpha; Y: gamma; Z: beta

The half-life of radioactive carbon is 5 000 years.

If the radioactive carbon content of a dead animal has an activity of 12 counts per gram per minute, and some have been found to have an activity of 3 counts per gram per minute, how old are the animal remains?

1.   ?    10 000 years
2.   ?    20 000 years
3.   ?    5 000 years
4.   ?    2 500 years

The mass of an isotope is 12 g and the half-life is 10 years.

Find the undecayed mass of this isotope after 20 years.

1.   ?    6.0 g
2.   ?    3.0 g
3.   ?    1.2 g
4.   ?    0.6 g

A radioactive source is placed 3 cm from a Geiger-Muller tube in air. The average count rate is 742 counts / minute.

1.   ?    alpha and beta only
2.   ?    alpha and gamma only
3.   ?    beta and gamma only
4.   ?    alpha, beta and gamma

A radioactive material gives a count rate of 8 000 counts per minute.

After twenty days, it gives a count rate of 500 counts per minute.

What is the half-life of the material?

1.   ?    4 days
2.   ?    5 days
3.   ?    20 days
4.   ?    80 days