A hospital physicist uses a gamma source to check whether a metal pipe is cracked. Fig. 1 shows a simplified nuclear change in the source. Gamma radiation i...
Question 1 Report
A hospital physicist uses a gamma source to check whether a metal pipe is cracked. Fig. 1 shows a simplified nuclear change in the source. Gamma radiation is high-energy electromagnetic radiation. Unlike alpha or beta emission, it does not alter the numbers of protons and neutrons in the nucleus. The detector outside the pipe records the intensity of radiation after it passes through the metal.
(a) What happens to the mass number during the change in Fig. 1? [1]
(b) What happens to the proton number during this change? [1]
(c) Describe what the star beside X means. [1]
(d) Which type of radiation is most suitable for passing through the metal pipe? [1]
(e) Give one safety precaution the physicist should use when handling the source. [2]
Answer Details
(a) In gamma emission, the nucleus loses energy but does not lose nucleons. The mass number stays the same. [1]
(b) Gamma emission does not change the number of protons, so the proton number stays the same. [1]
(c) The star means that X is an excited, higher-energy nucleus. [1]
(d) Gamma radiation is most suitable because it is highly penetrating and can pass through the metal pipe to reach the detector. [1]
(e) Use any two suitable precautions: keep exposure time short, maximise the distance from the source, and use lead shielding or store the source in a lead-lined box. Each reduces the radiation dose received. [2]
Download The App On Google Playstore
Everything you need to excel in your exams
