What particles are present in the nucleus of the oxygen nuclide ¹⁷₈O?

1.   ?    neutrons: 9 ; protons: 8
2.   ?    neutrons: 17 ; protons: 8
3.   ?    neutrons: 8 ; protons: 9
4.   ?    neutrons: 9 ; protons: 17

The table shows how the activity of a radioactive substance changes over a period of time.
(Allowance has been made for the background radiation.)

1.   ?    73 minutes
2.   ?    57 minutes
3.   ?    30 minutes
4.   ?    20 minutes

Deuterium ²₁H and ³₁H are two isotopes of hydrogen.
Compared to a deuterium atom, how many protons and neutrons does a tritium atom have?

1.   ?    protons: more ; neutrons: more
2.   ?    protons: more ; neutrons: same
3.   ?    protons: same ; neutrons: more
4.   ?    protons: same ; neutrons: same

A nucleus consists of 90 protons and 144 neutrons.

After emitting two beta particles followed by an alpha particle, this nucleus has .........................

1.   ?    86 protons and 140 neutrons
2.   ?    86 protons and 142 neutrons
3.   ?    90 protons and 140 neutrons
4.   ?    90 protons and 142 neutrons

When dealing with radioactive substances there are possible dangers.

Which statement is correct?

1.   ?    Beta particles can pass through skin and damage body cells.
2.   ?    Gamma radiation is more dangerous than alpha or beta because it has a longer half-life.
3.   ?    Materials that emit only alpha particles must be kept in thick lead containers.
4.   ?    Radioactive materials are safe to handle after two half-lives.

The diagram 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: alpha ; Y: gamma ; Z: beta
3.   ?    X: beta ; Y: alpha ; Z: gamma
4.   ?    X: beta ; Y: gamma ; Z: alpha

Two nuclides of neon are represented by the symbols below.

1.   ?    Electrons
2.   ?    Ions
3.   ?    Neutrons
4.   ?    Protons

When an animal dies, each gram of carbon in its body emits about 16 beta-particles each minute.
Some animal remains are discovered that emit about 4 beta-particles each minute from each gram of carbon.

How old are the animal remains, assuming that the half-life of radioactive carbon is 6 000 years?

1.   ?    1 500 years
2.   ?    3 000 years
3.   ?    12 000 years
4.   ?    24 000 years

In a sulphur nucleus there are 16 positively charged particles and 18 neutral particles.

Which are its proton and nucleon numbers?

1.   ?    Proton number : 16 ; Nucleon number : 18
2.   ?    Proton number : 16 ; Nucleon number : 34
3.   ?    Proton number : 18 ; Nucleon number : 16
4.   ?    Proton number : 18 ; Nucleon number : 34

What is the nucleon number (mass number) of a nuclide?

1.   ?    The number of neutrons
2.   ?    The number of protons
3.   ?    The number of neutrons and protons
4.   ?    The number of protons and electrons

The graph shows the count rate for a radioactive source over a few hours.

1.   ?    0
2.   ?    62.5
3.   ?    125
4.   ?    250

A nuclide is represented by ³⁵₁₇Cl.

How many neutrons and protons does each nucleus contain?

1.   ?    18 neutrons, 35 protons
2.   ?    18 neutrons, 17 protons
3.   ?    17 neutrons, 35 protons
4.   ?    17 neturons, 18 protons

Boxes which are used to store radioactive substance are usually lined with lead.

Why is this?

1.   ?    It is a good thermal conductor.
2.   ?    It prevents background radiation from entering the box and contaminating the contents.
3.   ?    It prevents much of the radiation from escaping into the surroundings.
4.   ?    It stop the box from being knocked over easily.

A radioactive sample has a half-life of 10 days.

1.   ?    A
2.   ?    B
3.   ?    C
4.   ?    D

Which type of radiation would be stop completely by a thin piece of cardboard?

1.   ?    Alpha-particles
2.   ?    Beta-particles
3.   ?    Gamma-rays
4.   ?    X-rays

A nucleus is represented by the symbol ⁸¹₃₇X.

What does the nucleus contain?

1.   ?    37 electrons and 44 neutrons
2.   ?    37 neutrons and 81 protons
3.   ?    37 protons and 44 neutrons
4.   ?    37 protons and 81 neutrons

The uranium atom ²³⁸₉₂U emits an alpha-particles to become thorium, which then emits a beta-particles to become protactinium.

1.   ?    89
2.   ?    90
3.   ?    91
4.   ?    95

The equation represents actinium decaying to thorium.

1.   ?    A helium nucleus
2.   ?    A neutron
3.   ?    An atom
4.   ?    An electron

In an experiment to find the half-life of a radioactive isotope, the following results were obtained.

1.   ?    2 min
2.   ?    4 min
3.   ?    6 min
4.   ?    8 min

How many electrons, neutrons and protons does an atom of iodine ¹²⁷₅₃I contain?

1.   ?    53 electrons, 74 neutrons, 53 protons
2.   ?    53 electrons, 127 neutrons, 53 protons
3.   ?    74 electrons, 74 neutron, 53 protons
4.   ?    74 electrons, 53 neutrons, 74 protons

Why are gamma rays not deflected by a magnetic field?

1.   ?    They are strongly penetrating.
2.   ?    They are weakly ionising.
3.   ?    They have no charge.
4.   ?    They have no mass.

Why are radioactive sources stored in boxes lined with lead?

1.   ?    Lead absorbs radiation and stops it from escaping into the room.
2.   ?    Lead absorbs the radioactive source and makes it safe to handle.
3.   ?    Lead completely stops the source from decaying and so make it lasts longer.
4.   ?    Lead slows down the rate which the radioactive source decays.