Radioactivity

Which French scientist is credited with discovering radioactivity in 1896?
1. Henri Becquerel
2. Pierre Curie
3. Antoine Lavoisier
4. Louis Pasteur
One of the elements discovered by Pierre and Marie Curie is named after the country of birth of Marie Curie.
Which element is this?
1. Polonium
2. Francium
3. Americium
4. Germanium
Which one of these metals is used as a shield against radioactive emissions?
1. Lead
2. Radium
3. Uranium
4. Gold
Which one of the following statements is NOT correct concerning alpha-particles?
1. They can penetrate thick sheets of lead
2. They have a positive charge
3. They are emitted from unstable nuclei
4. They are composed of helium nuclei
Which one of the following is a property of beta-particles?
1. They are negatively charged.
2. They have the greatest penetrating power.
3. They are heavier than alpha-particles.
4. They do not have mass.
Which one of the following is NOT a property of gamma radiation?
1. It can be deflected in magnetic fields.
2. It has a high penetrating power.
3. Gamma radiation has no charge.
4. Gamma radiation nas no mass.
Which one of the following radioisotopes is used in medicine to kill cancerous cells?
1. cobalt-60
2. uranium-238
3. carbon-14
4. americium-241
Radioactivity may be detected by which one of the following instruments?
1. Geiger-Muller tube
2. Atomic clock
3. Multimeter
4. Ratemeter
Radium-226 may decay by the emission of an alpha-particle. Which one of the following sets of products would result in such a decay?
Note - Radium has an atomic number of 88.
Which one of the following reactions is NOT correct?
The half-life of a radioisotope is
1. the time taken for half of the nuclei in any given sample to decay.
2. the time taken for half of the nuclei in any given sample to disappear.
3. the number of nuclei of that radioisotope that will decay in half an hour.
4. the same for all isotopes of the same element.
The half-life of technetium-99 is 6 hours.
How much of a 100 milligram sample of technetium-99 will remain after 30 hours?
1. 3.125 mg
2. 1.56 mg
3. 6.25 mg
4. 12.5 mg
The graph shows how the radioactivity of a particular isotope varies with time.
What is the half-life of this isotope?
1. 5 days
2. 10 days
3. 2.5 days
4. 12.5 days
The reading taken on a ratemeter due to natural radioactivity is known as the
1. background count
2. background rate
3. background noise
4. background sound
Which one of the following would most likely be the penetration depth of an alpha-particle?
1. 4 to 6 cm of air
2. 4 to 6 cm of aluminium
3. 4 to 6 m of air
4. 4 to 6 cm of lead
Which one of the following is true when a nucleus undergoes radioactive decay?
1. The unstable nucleus loses energy.
2. Alpha-particles are always emitted.
3. Beta-particles are always emitted.
4. A new element is always formed.
Which one of the following would NOT be a use of radioisotopes?
1. Dating of silverware found in an archaeological site
2. Tracing leaks from underground pipes
3. Putting a date on the remains of a dinosaur
4. Irradiation of tropical fruits before consuming them
In beta decay, the total number of nucleons
1. remains the same
2. decreases by two
3. decreases by four
4. increases by one
When beta decay occurs in a radioactive isotope, the atomic number (Z) always
1. increases by one
2. stays the same
3. decreases by one
4. increases by two
In the following equation for radioactive decay, what are the values of A and Z?
1. A = 237, Z = 93
2. A = 239, Z = 93
3. A = 239, Z = 91
4. A = 237, Z = 91
Which one of the following is a property of gamma rays?
1. They have no mass or charge.
2. Its symbol is
3. They are negatively charged.
4. They have poor penetrating ability.
Which one of the following sets of products are from the beta-decay of Pb-212, where the atomic number of lead is 82?
How much of a radioisotope will have decayed after two half-lives?
1. 75%
2. 50%
3. 25%
4. 12.5%
The process of determining the age of a fossil is known as
1. carbon dating
2. radioactive dating
3. smoke detecting
4. irradiation
What is an alpha particle?
1. A helium nucleus
2. A hydrogen nucleus
3. A fast moving electron
4. Two protons and four neutrons
Alpha, beta and gamma radiations have different penetrating powers.
Select from the following options, the correct answer for increasing penetrating power.
1. Alpha, beta, gamma
2. Alpha, gamma, beta
3. Beta, gamma, alpha
4. Gamma, beta, alpha
Which one of the following is the correct equation for the nuclear reaction involved in the beta decay of the carbon-14 atom?
Name the scientist from the list below who is credited with the discovery in 1896 that uranium salts emit radiation.
1. Henri Becquerel
2. Pierre Curie
3. William Crookes
4. J J Thomson
5. Ernest Rutherford
6. Neils Bohr
7. John Dalton
Which one of the following does not occur in a nuclear reaction?
1. It involves a rearrangement of electrons.
2. Nuclear radiation is released.
3. There is a change in mass.
4. New elements are made.
Polonium decays emitting an alpha particle.

What are the values of x, y and Z in the equation?
1. x = 82, y = 206, Z = Pb
2. x = 206, y = 82, Z = Pb
3. x = 83, y = 206, Z = Bi
4. x = 82, y = 204, Z = Pb
What change occurs in the nucleus of an atom when it undergoes beta emission?
1. The outer shell of electrons is filled.
2. A high speed electron is produced.
3. There is a release of energy.
4. A proton is produced.
5. The number of neutrons decreases by one.
The world's oldest shoe was recently found in Armenia. Its age was measured using carbon dating. Why does the carbon–12 to carbon–14 isotope ratio in the shoe change over the 5500 years since the shoe was made.
1. The carbon-14 decays over time to nitrogen-14.
2. The carbon-14 changes to carbon-12.
3. More carbon-14 is formed as carbon-12 decays.
4. Carbon-14 and carbon-12 both decay at different rates.
Which one of the following statements describes an isotope?
1. The spontaneous breakup of unstable nuclei, followed by the emission of radiation.
2. Different atoms of same element having different mass numbers.
3. The time taken for half of the atoms in a sample to decay.
4. High energy electromagnetic radiation with high penetrating ability.
Americium–241 is a radioactive isotope used in domestic smoke detectors. Americium–241
has a half-life of 432 years and decays by emitting alpha particles to produce neptunium.
What are the values of A and Z in the following nuclear equation for the alpha decay of an americium–241 nucleus?
1. A = 237, Z = 93
2. A = 241, Z = 96
3. A = 96, Z = 241
4. A = 245, Z = 97
Alpha particles are hazardous to human health. Which one of the following is not a risk associated with exposure to alpha radiation?
1. It causes high cholesterol.
2. It causes cancer.
3. It causes ionisation of cells.
4. It causes mutation.
Americium-241 is used in smoke detectors. Householders are advised to replace the batteries in smoke detectors regularly. However, the americium–241 does not need to be replaced regularly.
Why is this?
1. Americium-241 has a very long half-life.
2. Americium-241 is too dangerous to handle.
3. There is no facility for recycling radioactive material.
4. Americium-241 is not radioactive.
Why would the occupants of a house fitted with smoke detectors containing americium–241 not be at risk from alpha radiation emitted by these devices.
1. It has very low penetrating power through the air.
2. Alpha radiation is not harmful.
3. The occupants wear protective clothing at all times.
4. Alpha radiation has very low ionizing power.
Isotopes of the same element have different
1. numbers of neutrons
2. atomic numbers
3. numbers of electrons
4. numbers of protons
Radioactive substances must be handled carefully because they emit
1. radiation which damage living cells
2. electrically charged particles
3. protons, neutrons and electrons
4. rays which makes substances radioactive
When an isotope loses a beta-particle, its atomic number
1. increases by one
2. decreases by one
3. increases by two
4. decreases by two

Radioactivity

Multiple Choice Quiz