A radioactive nucleus emits either an α-particle or a β-particle. What are the products of these two types of radioactive emission?
A
B
C
D
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 10 min
B 20 min
C 40 min
D 60 min
The graph shows how the decay rate of a radioactive source changes with time. What will be the activity at 8 days?
A 0 decays / s
B 125 decays / s
C 250 decays / s
D 500 decays / s
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?
A 2 days
B 4 days
C 8 days
D 12 days
Radioactive materials should be handled carefully. Which safety precaution does not reduce the risk to people using a radioactive material?
A keeping the material a long distance from people
B keeping the material at a low temperature
C using lead screening between the material and people
D using the material for only a short time
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 handling the source with long tongs
handling the source with long tongs
B keeping the temperature of the source low
C opening all windows in the laboratory
D washing his hands before leaving the laboratory
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?
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?
A 25 counts / s
B 192 counts / s
C 200 counts / s
D 208 counts / s
Which statement about α-radiation is correct?
A It is a stream of fast-moving electrons.
B It is a form of electromagnetic radiation.
C It is more highly ionising than γ-radiation.
D It is more penetrating than β-radiation.
α, β and γ-radiations are emitted by radioactive substances. Which statement is correct?
A α-radiation consists of charged particles and is the most highly ionising radiation.
B β-radiation consists of charged particles and is the most penetrating radiation.
C β-radiation consists of uncharged particles and is the least highly ionising radiation.
D γ-radiation consists of uncharged particles and is the least penetrating radiation.
The diagram shows a box used for storing radioactive sources. Which material is best for lining the box to prevent the escape of most radioactive emissions?
A aluminium
B copper
C lead
D steel
The diagram shows a radioactive source, a thick aluminium sheet and a radiation detector. The radiation detector shows a reading greater than the background reading. Which type of radiation is being emitted by the source and detected by the detector?
A α-radiation
B β-radiation
C γ-radiation
D infra-red radiation
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 α-particles only
B β-particles only
C either α-particles or β-particles
D γ-rays only
A certain element has several radioactive isotopes. Which statement about these isotopes is correct?
A They must have different numbers of electrons orbiting their nuclei.
B They must have the same number of neutrons in their nuclei.
C They must have the same number of nucleons in their nuclei.
D They must have the same number of protons in their nuclei.
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