Radiation and the Universe Higher Exam revision questions and answers Madeley High School Q.The names of three different processes are given in List A. Where these processes happen is given in List B. Draw a line to link each process in List A to where the process happens in List B. Draw only three lines. List A style='height:.pt'>proc ess List B Where it happens in a star fusion in a nuclear reactor chain reaction in a smoke precipitator alpha decay in the nucleus of an atom Q2.The diagram represents an atom of beryllium. The three types of particle that make up the atom have been labelled. (Total 3 marks) (a) Use the labels from the diagram to complete the following statements. Each label should be used once. The particle with a positive charge is.... The particle with the smallest mass is.... The particle with no charge is...(2) Page
(b) What is the mass number of a beryllium atom? Draw a ring around your answer. 4 5 9 3 Give a reason for your answer. (2) (Total 4 marks) Q3. (a) The names of the three types of nuclear radiation are given in List A. Some properties of these types of radiation are given in List B. Draw a straight line to link each type of radiation in List A to its correct property in List B. Draw only three lines. List A Type of nuclear radiation List B Property of radiation Has the same mass as an electron Alpha Very strongly ionising Beta Passes through 0 cm of aluminium Gamma Deflected by a magnetic field but not deflected by an electric field (3) Page 2
(b) The diagram shows a system used to control the thickness of cardboard as it is made. Madeley High School The cardboard passes through a narrow gap between a beta radiation source and a radiation detector. The table gives the detector readings over hour. Time Detector reading 08:00 50 08:5 48 08:30 5 08:45 0 09:00 49 (i) Between 08:00 and 08:30, the cardboard is produced at the usual, correct thickness. Explain how you can tell from the detector readings that the cardboard produced at 08:45 is thicker than usual. (2) Which would be the most suitable half-life for the beta source? Draw a ring around your answer. six days six months six years () Page 3
(iii) This control system would not work if the beta radiation source was replaced by an alpha radiation source. Why not? () (Total 7 marks) Q4. Some rocks inside the Earth contain a radioactive element, uranium-238. When an atom of uranium-238 decays, it gives out an alpha particle. (a) The following statement about alpha particles was written by a student. The statement is not correct. Change one word in the statement to make it correct. Write down your new statement. () Page 4
(b) The graph shows how the count rate from a sample of uranium-238 changes with time. The graph can be used to find the half-life of uranium-238. The half-life is 4 500 million years. (i) Draw on the graph to show how it can be used to find the half-life of uranium -238. There is now half as much uranium-238 in the rocks as there was when the Earth was formed. How old is the Earth? Draw a ring around your answer. () 2250 million years 4500 million years 9000 million years () (iii) If a sample of uranium-238 were available, it would not be possible to measure the half-life in a school experiment. Explain why. (2) (Total 5 marks) Page 5
Q5.(a) The names of three types of radiation are given in List A. Some properties of these three types of radiation are given in List B. Draw one line from each type of radiation in List A to its correct property in List B. List A Type of radiation alpha beta gamma List B Property of radiation will pass through paper but is stopped by thin metal has the shortest range in air will not harm human cells is very weakly ionising (3) (b) The radioactive isotope iodine-23 can be used by a doctor to examine the thyroid gland of a patient. The iodine, taken as a tablet, is absorbed by the thyroid gland. The gamma radiation emitted as the iodine atoms decay is detected outside the body. The doctor uses an isotope emitting gamma radiation to examine the thyroid gland rather than an isotope emitting alpha or beta radiation. Page 6
Which one of the following gives a reason why gamma radiation is used? Tick ( ) one box. Gamma radiation will pass through the body. Gamma radiation is not deflected by a magnet. Gamma radiation has a long range in air. () (c) Iodine-23 has a half-life of 3 hours. Use a word from the box to complete the sentence. all half most After 3 hours... of the iodine-23 atoms the thyroid absorbed have decayed. () (d) Iodine-23 and iodine-3 are two of the isotopes of iodine. Draw a ring around the correct answer to complete the sentence. electrons The nucleus of an iodine-23 atom has the same number of neutrons as the protons nucleus of an iodine-3 atom. () (Total 6 marks) Page 7
Q6. (a) The diagrams represent three atoms, X, Y and Z. Which of these atoms are isotopes of the same element? Give a reason for your answer. (2) (b) In a star, nuclei of atom X join to form nuclei of atom Y. Complete the sentences. The process by which nuclei join to form a larger nucleus is called nuclear.... This is the process by which a star releases.... (2) Page 8
(c) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. A star goes through a lifecycle. Describe the lifecycle of a star like the Sun. (6) (Total 0 marks) Page 9
Q7. The pie chart shows the sources of the background radiation and the radiation doses that the average person in the UK is exposed to in one year. Radiation dose is measured in millisieverts (msv). (a) (i) What is the total radiation dose that the average person in the UK receives? Total radiation dose =... msv () A student looked at the pie chart and then wrote down three statements. Which one of the following statements is a correct conclusion from this data? Put a tick ( ) in the box next to your answer. In the future, more people will be exposed to a greater proportion of radon gas. Page 0
People that have never had an X-ray get 50% of their radiation dose from radon gas. The radiation dose from natural sources is much greater than from artificial sources. () (b) The concentration of radon gas inside a home can vary from day to day. In some homes, the level can build up to produce a significant health risk. It is estimated that each year 000 to 2000 people die because of the effects of radiation from radon gas. (i) It is not possible to give an exact figure for the number of deaths caused by the effects of radiation from radon gas. Why? () The table gives data for the radiation levels measured in homes in 4 different parts of the UK. The radiation levels were measured using two detectors, one in the living room and one in the bedroom. The measurements were taken over 3 months. Area of the UK Number of homes in the area Number of homes in the sample Average radiation level in Bq/m 3 Maximum radiation level in Bq/m 3 A 590 000 60 5 8 B 484 000 30 8 92 C 22 000 68 000 62 0 000 D 38 000 35 300 95 6 900 Page
Give one reason why the measurements were taken over 3 months using detectors in different rooms. () (iii) Use information from the table to suggest why a much higher proportion of homes were sampled in areas C and D than in areas A and B. (2) (Total 6 marks) Q8. Some types of food are treated with gamma radiation. Low doses of radiation slow down the ripening of fresh fruit and vegetables while higher doses of radiation kill the bacteria that make the food go off. (a) (i) What is gamma radiation? () Food packed in crates or boxes can be treated using this method. Why must a source that emits gamma radiation be used? () iii) A suitable source of gamma radiation is the isotope caesium 37. Complete the following sentence by choosing the correct word from the box. electrons neutrons protons An atom of caesium 37 has two more... than an atom of caesium 35. () Page 2
(b) The diagram shows how a conveyor belt can be used to move food past the radioactive source. (i) How do the concrete walls reduce the radiation hazard to workers outside the food treatment area? () Suggest one way that the dose of radiation received by the food could be increased other than by changing the radioactive source. () (c) Some people may not like the idea of eating food treated with radiation. (i) What evidence could a food scientist produce to show that food treated with radiation is safe to eat? Page 3
(2) The diagram shows the sign displayed on food treated with radiation. Why is it important for people to know which foods have been treated with radiation? () (Total 8 marks) Q9. (a) The graph shows how the count rate from a sample containing the radioactive substance cobalt-60 changes with time. Page 4
(i) What is the range of the count rate shown on the graph? Madeley High School From... counts per second to... counts per second. () How many years does it take for the count rate to fall from 200 counts per second to 00 counts per second? Time =... years () (iii) What is the half-life of cobalt-60? Half-life =... years () (b) The gamma radiation emitted from a source of cobalt-60 can be used to kill the bacteria on fresh, cooked and frozen foods. Killing the bacteria reduces the risk of food poisoning. The diagram shows how a conveyor belt can be used to move food past a cobalt-60 source. (i) Which one of the following gives a way of increasing the amount of gamma radiation the food receives? Put a tick ( ) in the box next to your answer. Increase the temperature of the cobalt-60 source. Make the conveyor belt move more slowly. Move the cobalt-60 source away from the conveyor belt. () Page 5
To protect people from the harmful effects of the gamma radiation, the cobalt-60 source has thick metal shielding. Which one of the following metals should be used? Draw a ring around your answer. aluminium copper lead () (c) A scientist has compared the vitamin content of food exposed to gamma radiation with food that has not been exposed. The table gives the data the scientist obtained when she tested kg of cooked chicken. Vitamin Food not exposed to gamma radiation Mass in milligrams Food exposed to gamma radiation Mass in milligrams B6.22.35 B2 2.00 28.00 E 3.30 2.5 Niacin 58.00 55.50 Riboflavin 2.0 2.25 Considering only this data, which one of the following is a correct conclusion? Put a tick ( ) in the box next to your answer. Vitamin content is not affected by gamma radiation. Gamma radiation completely destroys some types of vitamin. Exposure increased the content of some types of vitamin. () (Total 6 marks) Page 6
Q0. The diagram shows how the thickness of aluminium foil is controlled. The thicker the aluminium foil, the more radiation it absorbs. (a) The designers used a beta radiation source for this control system. (i) Why would an alpha radiation source be unsuitable in this control system? () Why would a gamma radiation source be unsuitable in this control system? () (b) The substance used in the beta radiation source is radioactive. (i) Why are some atoms radioactive? () Explain why radiation is dangerous to humans. (2) (Total 5 marks) Page 7
M.three lines correct allow mark for each correct line if more than line is drawn from a box in List A, mark each line incorrect [3] M2.(a) proton all 3 in correct order electron neutron allow mark for correct do not accept letters p, e, n 2 (b) 9 reason only scores if 9 is chosen number of neutrons and protons [4] Page 8
M3. (a) mark for each correct line if more than line is drawn from any box in List A, none of those lines gain any credit 3 (b) (i) (the detector) reading had gone down it equals detector reading accept the reading in the table is the smallest accept 0 is (much) lower than other readings / a specific value eg 50 do not accept this answer if it indicates the readings are the thickness more beta (particles / radiation) is being absorbed / stopped accept radiation for beta particles / radiation accept fewer particles being detected six years (iii) alpha would not penetrate the cardboard accept the basic property alpha (particles) cannot pass through paper / card accept alpha (particles) are less penetrating (than beta) Page 9
range in air is neutral Madeley High School [7] M4. (a) alpha particles cannot pass through do not accept gamma particles or alpha particles can pass through a very thin sheet of paper / card credit answers where correct amendments are made to boxed statement (b) (i) horizontal and vertical line drawn at correct positions on the graph accept a cross drawn at 4500 / 500 on the curve or two pairs of lines drawn, for example, at 600 and 300 accept a horizontal line drawn at 500 on its own do not accept vertical lines only 4500 million years (iii) half-life too long do not accept simply its half-life is 4500 million years no (measurable) change in count rate do not accept have not got the equipment do not accept it s harmful (to children) if neither of the above points scored, accept not enough time to measure it for mark [5] Page 20
M5.(a) 3 lines correct allow mark for each correct line if more than one line is drawn from any type of radiation box then all of those lines are wrong 3 (b) Gamma radiation will pass through the body (c) half (d) protons [6] M6. (a) Y and Z both required, either order same number of protons (b) fusion correct order only Page 2
energy (c) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. No relevant content. 0 marks There is a brief description of the life cycle of a star like the sun. Level ( 2 marks) There is some description of the life cycle of a star like the sun. Level 2 (3 4 marks) There is a clear and detailed description of the life cycle of a star like the sun. Level 3 (5 6 marks) examples of the physics points made in the response to score full marks either the term red giant or white dwarf must be used gases and dust pulled together by gravity nuclear fusion begins when forces are balanced star is stable expands cools becomes a red giant do not accept red supergiant shrinks temperature rises glows much brighter becomes a white dwarf any mention of supernova negates a mark any mention of black hole negates a mark individual points must be linked in a correct sequence [0] Page 22
M7. (a) (i) 2.5 The radiation dose from natural sources is much greater than from artificial sources. (b) (i) other factors may be involved accept a specific suggestion eg they may be exposed to other types of radiation accept cannot be sure (in many cases) that the cause of death is radon (poisoning) any one from: different concentrations in different rooms to average out daily fluctuations accept to find an average accept to make the result (more) reliable / valid do not accept to make more accurate on its own (iii) average level (much) higher (in C and D) accept converse some homes have very high level (in C and D) accept maximum level in A and B is low ormaximum level in some homes (in C and D) is very high accept higher radiation levels (in C and D) for mark [6] Page 23
M8. (a) (i) electromagnetic (wave / radiation) accept em (wave / radiation) ignore reference to frequency (iii) gamma can penetrate the crate / box / packaging accept converse (but must relate to both alpha and beta) ignore just gamma radiation kills bacteria accept can get through to food neutrons (b) (i) absorb gamma / radiation accept it stops / reduces the radiation any one from: slow down the conveyor belt food does more than one circuit stay on the conveyor belt longer food closer to the source / radiation ignore larger doses / use more of the source ignore thinner packaging (c) (i) idea of testing food on humans / animals no (measured) ill effects or monitor their health accept monitor people that have eaten the food accept a measurement / comparison for mark eg measure the amount of radiation in treated food comparison plus a reason for the comparison would get 2 marks eg idea of measuring level of radiation in treated food with no measurable increase in level = 2 marks or comparing it to untreated food = 2 marks Page 24
so can make own decision about eating or not eating treated food accept may be against their religious / moral views accept some people prefer food that hasn t been tampered with ignore in case they don t like the idea of eating treated food accept don t want to eat treated food ignore might be allergic to the food eg think it will give them cancer = 0 marks think it will give you cancer so I need to know so that I can choose = mark [8] M9. (a) (i) 200 to 50 accept either order 5.3 accept values between 5.2 and 5.4 inclusive (iii) 5.3 accept values between 5.2 and 5.4 inclusive ortheir (a) (b) (i) Make the conveyor belt move more slowly lead (c) Exposure increased the content of some types of vitamin. [6] Page 25
M0. (a) (i) cannot penetrate aluminium allow can only pass through air / paper too weak is neutral gamma rays not affected (by aluminium) allow all / most (gamma rays) to pass through too strong is neutral danger is neutral (b) (i) (nuclei) unstable causes harm / damage to body / cells allow radiation sickness detail e.g., causes mutations / causes cancer / damages DNA / damages chromosomes allow two effects for 2 marks [5] Page 26