<p>Q1.(a) Table 1 gives some properties of alpha, beta and gamma radiation. Table 1</p><p>Radiation Range in air Effect of a magnetic field</p><p>Alpha particle ...... deflected a small amount</p><p>Beta particle about 1m deflected a lot</p><p>Gamma ray unlimited ...... </p><p>(i) Which one of the following describes an alpha particle?</p><p>Tick ( ) one box. It is the same as the nucleus of a helium atom.</p><p>It is an electron.</p><p>It is a negative ion.</p><p>(1)</p><p>(ii) Complete Table 1 by adding the missing information. (2)</p><p>(b) Table 2 gives information about four radioactive isotopes. Table 2</p><p>Isotope Type of radiation Half-life emitted</p><p> iridium-192 gamma ray 74 days</p><p> polonium-210 alpha particle 138 days</p><p> polonium-213 alpha particle less than 1 second</p><p> technetium-99 gamma ray 6 hours</p><p>Two isotopes of polonium are given in the table. In terms of particles in the nucleus:</p><p>(i) how are these two isotopes the same</p><p>...... (1)</p><p>Page 1 (ii) how are these two isotopes different?</p><p>...... (1)</p><p>(c) To monitor the blood flow through a patientߣ s heart, a doctor injects the patient with a very small dose of technetium-99. The gamma radiation detected outside of the patient’s body allows the doctor to see if the heart is working correctly.</p><p>(i) Explain why technetium-99 is more suitable for this use than polonium-210.</p><p>...... </p><p>...... </p><p>...... </p><p>...... (2)</p><p>(ii) Explain why technetium-99 is more suitable for this use than iridium-192.</p><p>...... </p><p>...... </p><p>...... </p><p>...... (2)</p><p>(d) Technetium-99 (Tc) is produced by the beta decay (β) of an isotope of molybdenum (Mo).</p><p>The decay can be represented by the equation below.</p><p>Complete the equation by writing the correct number in each of the two boxes.</p><p>(2) (Total 11 marks)</p><p>(e) When a thorium-230 nucleus decays, it emits radiation and changes into radium-226.</p><p>What type of radiation, alpha, beta or gamma, is emitted by thorium-230?</p><p>...... </p><p>Explain the reason for your answer.</p><p>Page 2 ...... </p><p>...... </p><p>...... </p><p>...... </p><p>...... (3)</p><p>M1.(a) (i) It is the same as the nucleus of a helium atom. 1</p><p>(ii) (about) 5 cm accept any number between 2 and 8 cm 1</p><p> not deflected accept none 1</p><p>(b) (i) number of protons accept same atomic / proton number 1</p><p>(ii) numbers of neutrons accept different mass numbers 1</p><p>(c) (i) because polonium-210 is an alpha emitter 1</p><p> and alpha particles cannot be detected outside bodyor alpha particles produce heavy ionisation 1</p><p>(ii) because iridium-192 has a long(er) half life 1</p><p> and so will be radioactive for longer 1 Page 3 (d) 99 1</p><p>42 1 [11]</p><p>(e) alpha (particle) reason may score even if beta or gamma is chosen 1</p><p> mass number goes down by 4or number of protons and neutrons goes down by 4 or number of neutrons goes down by 2 candidates that answer correctly in terms of why gamma and beta decay are not possible gain full credit 1</p><p> atomic / proton number goes down by 2or number of protons goes down by 2 accept an alpha particle consists of 2 neutrons and 2 protons for 1 mark</p><p> accept alpha equals 42He or 42α for 1 mark an alpha particle is a helium nucleus is insufficient for this mark 1 [8]</p><p>Page 4</p>