SSS Chem 5105, 5107 Prelim 2021 P4_Final

5105/5107/04/Prelim/21 [Turn over SINGAPORE SPORTS SCHOOL PRELIMINARY EXAMINATION SECONDARY 4 NORMAL (ACADEMIC) ___________________________________________________________________ SCIENCE 5105/04; 5107/04 Paper 4 (Chemistry) 16 AUGUST 2021 Papers 3 and 4: 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. _________________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write your class, index number and name on all the work you hand in. Write in a dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams, graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in Section A and any two questions in Section B. The use of an approved scientific calculator is expected, where appropriate. In calculations, you should show all the steps in your working, giving your answer at each stage. You are advised to spend no longer than 30 minutes on Paper 3. You may proceed to answer Paper 4 as soon as you have completed Paper 3. A copy of the Periodic Table is printed on page 10. At the end of the examination hand in your answers to Paper 3 and Paper 4 separately. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 9 printed pages and 1 blank page. CANDIDATE NAME CLASS INDEX NUMBER For Examiner’s Use Section A / 14 Section B /16 Total 30

2 5105/5107/04/Prelim/21 [Turn over For Examiner’s Use Section A Answer all the questions in the spaces provided. 1 Sulfur is an element in Group VI of the Periodic Table. (a) Define the term element. [1] (b) The diagram below shows how the temperature changes as a sample of solid sulfur is heated. (i) What is the boiling point of sulfur? boiling point: °C [1] (ii) Between which two letters is there only solid present? and [1] (iii) In terms of kinetic particle theory, explain what happens in the region from B to C. [2] [Total: 5]

3 5105/5107/04/Prelim/21 [Turn over For Examiner’s Use 2 The electronic structures of five atoms are given below. Answer the following questions about these atoms. Each atom may be used once, more than once or not at all. Which atom A, B, C, D or E, (a) has a total of 8 electrons, [1] (b) is in Group III of the Periodic Table, [1] (c) has 11 protons in its nucleus, [1] (d) is a noble gas, [1] (e) forms a stable ion with a 1– charge? [1] [Total: 5] 3 The diagram shows part of the structures of two substances X and Y, at room temperature and pressure. (a) In the space below, draw the “dot-and-cross” diagram for a molecule of substance Y. Show only the valence electrons. [2]

4 5105/5107/04/Prelim/21 [Turn over For Exami