0654 Radioactivity Quiz

A certain element has several isotopes. Which statement about these isotopes is correct?

A very important experiment increased scientists’ understanding of the structure of matter. In the experiment, particles scattered as they passed through a thin metal foil. Which particles were used, and to which conclusion did the experiment lead?

Below are four statements about isotopes of a certain element. Which statement about the isotopes must be correct?

The scattering of α-particles by a thin metal foil supports the nuclear model of an atom. Why are α-particles used rather than neutrons?

The arrangement shown is used to check whether the flour inside a cardboard packet is above a certain level. If it is above this level, the flour absorbs the radiation from the source so that it doesn’t reach the detector. Which type of radiation is suitable to use?

A radioactive nucleus contains 128 nucleons. It emits a β-particle. How many nucleons are now in the nucleus?

Which diagram could represent the structure of a neutral atom?

A reading is taken every 10 minutes of the number of emissions per second from a radioactive source. The table shows the readings. What is the half-life of the source?

 A radioactive decay can be represented as shown. The equation is incomplete. In this decay, the nucleus changes by:

The graph shows how the decay rate of a radioactive source changes with time. What will be the decay rate at 8 days?

Sodium-24 decays to magnesium-24 according to the equation shown. What is the emitted particle?

A radioactive nucleus emits either an α-particle or a β-particle. What are the products of these two types of radioactive emission?

 Radioactive materials should be handled carefully. Which safety precaution does not reduce the risk to people using a radioactive material?

A scientist carries out an experiment using a sealed source which emits β-particles. The range of the β-particles in the air is about 30 cm. Which precaution is the most effective to protect the scientist from the radiation?

A beam of γ-rays passes between two charged metal plates as shown in the diagram. How do the γ-rays pass between the two charged plates?

A radioactive source emits three types of radiation R, S and T. The diagram shows an experiment set up to study the penetrating properties of R, S and T. Which types of radiation are R, S and T?

The half-life of a radioactive substance is 10 minutes. A sample of the radioactive substance contains 2000 nuclei. How many radioactive nuclei were in the sample half an hour earlier?

The graph shows the activity of a radioactive source over a period of time. What is the half-life of the source?

 Why are some radioactive sources stored in boxes made from lead?

A radioactive nucleus emits a β-particle. What happens to the proton number (atomic number) of the nucleus?

Which shows the relative ionising effects and penetrating abilities of α-particles and β-particles?

A powder contains 400 mg of a radioactive material that emits α-particles. The half-life of the material is 5 days. What mass of that material remains after 10 days?

A radioactive nucleus emits either an α-particle or a β-particle. What are the products of these two types of radioactive emission?

A sample of a radioactive isotope has an initial rate of emission of 128 counts per minute and a half-life of 4 days. How long will it take for the rate of emission to fall to 32 counts per minute?

Which row describes the nature of α-particles and of γ-rays?

The diagram shows the paths of three different types of radiation, X, Y and Z. Which row in the table correctly identifies X, Y and Z?

 Which row gives the properties of the radiation from radioactive materials?

 In a laboratory, a detector of ionising radiation records an average background count rate of 8 counts per second. A radioactive source is now placed close to the detector. The count rate on the detector rises to 200 counts per second. What is the count rate due to radiation from the radioactive source?

Which statement about α-radiation is correct?

A radioactive source produces a count rate on a detector of 1600 counts/s. After 32 hours the count rate has fallen to 100 counts/s. Both count rates have been corrected for background radiation. What is the half-life of the source?

 α, β and γ-radiations are emitted by radioactive substances. Which statement is correct?

Which row shows the nature and the penetrating ability of β-particles?

A radioactive isotope is placed near a detector. The readings on the detector are corrected for background radiation and recorded every hour. The table shows the corrected readings. What is the half-life of the isotope?

A student investigates how the radiation from a radioactive source changes with time. The table shows the results from the detector used by the student. The experiment is repeated by many other students, who also measure the count rate per minute. The half-life of the source is known to be exactly 2.0 minutes. Why is the measured count rate always greater than half the previous value?

In a cathode-ray tube, a hot tungsten cathode releases particles by thermionic emission. What are these particles?