Which of these atoms are isotopes of the same element? (2) The process by which nuclei join to form a larger nucleus is called

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Barnard Gregory
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1 Q. (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. 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.... Page

2 (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 2

3 Q2. (a) Complete the sentences about atoms. In an atom, the number of electrons is equal to the number of.... All atoms of an element have the same number of.... Isotopes of the same element have different numbers of.... (3) Complete the sentence. When an atom of a radioactive element emits alpha radiation, an atom of a different element is formed. A different element is formed because the radioactive element has lost.... () (Total 4 marks) Q3. In the early part of the 20th century scientists used the plum pudding model to explain the structure of the atom. (a) What did scientists think that the pudding part of the atom was? () The scientists Geiger and Marsden devised an experiment to test the plum pudding model. They fired positively charged alpha particles at a very thin sheet of gold foil. They then measured the different paths taken by the alpha particles. Page 3

4 List A gives some of the observations from the experiment. List B gives the conclusions reached from the observations. Draw one line from each observation in List A to the conclusion reached in List B. List A Observation List B Conclusion (c) Following the work of Geiger and Marsden, the plum pudding model of the atom was replaced by the nuclear model of the atom. Explain why it is sometimes necessary for scientists to replace a scientific model. (Total 5 marks) Page 4

5 Q4. (a) The diagram shows what can happen when the nucleus of a uranium atom absorbs a neutron. (i) What name is given to the process shown in the diagram?... () (ii) Explain how this process could lead to a chain reaction. You may wish to add further detail to the diagram to help your answer (iii) How does the mass number of an atom change when its nucleus absorbs a neutron?... () Page 5

6 Uranium-235 is used as a fuel in some nuclear reactors. Source: adapted from Physics Matters, by Nick England. Published by Hodder and Stoughton, 989. Reproduced by permission of Hodder and Stoughton Ltd. The reactor contains control rods used to absorb neutrons. Suggest what happens when the control rods are lowered into the reactor (Total 6 marks) Page 6

7 M. (a) Y and Z both required, either order same number of protons fusion correct order only 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 Page 7

8 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] M2. (a) protons protons accept electrons neutrons protons reject mass [4] M3. (a) (mass of) positive charge three lines correct Page 8

9 allow mark for correct line if more than line is drawn from a box in List A then all those lines are incorrect 2 (c) new scientific evidence / data is obtained which cannot be explained by the model [5] M4. (a) (i) (nuclear) fission accept fision providing clearly not fusion (ii) (released) neutrons are absorbed by further (uranium) nuclei accept hit nuclei for absorbed / hit do not accept atom for nuclei more neutrons are released (when new nuclei split) accept for both marks a correctly drawn diagram Page 9

10 (iii) increases by or goes up to 236 any two from: (more) neutrons are absorbed accept there are fewer neutrons (chain) reaction slows down / stops accept keeping the (chain) reaction controlled less energy released accept heat for energy accept gases (from reactor) are not as hot 2 [6] Page 0

Radiation and the Universe Higher Exam revision questions and answers

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.