Combined Science Revision Question 1 Outline how industrial gases are manufactured from air. Solution 1 Air is cooled to -78°C. Water and carbon dioxide are removed as solids. The remaining air is further cooled by a process of rapid compression and expansion until it reaches a temperature of -200°C. At this temperature all gases are …
Uses of common elements and compounds This is a list of commonly asked uses of substances in O level Chemistry and Combined Science exams. Uses of oxygen Medical purposes – In hospitals, oxygen is given to some people who are injured or ill with disease that damage the lungs and stop them from absorbing oxygen …
Combined Science Chemistry Section Multiple Choice (Page 1) The diagram shows the electronic structure of an atom of a certain element, Z. Z will most likely form: A. Z+ ions B. Z2+ ions C. Z– ions D. Z2- ions For which one of the following substances is the bonding correctly described? Substance Bonding A Argon …
Mixed Revision Questions and Answers (Page 1) Question 1 Use the table below to answer the questions that follow: Substance pH A 1 B 5 C 7 D 9 E 14 a) Which substance is a weak alkali? b) Which substance could be water? c) Which substance is a weak acid? d) Which substance could …
O level Physics and Chemistry Exam Assessment Many students find Physics and Chemistry exams tough and that is the reason why schools traditionally select only A classes only to do subjects such as chemistry, biology and physics. However anyone can do sciences. This guide will help you if you want to pass the exams. Assessment …
Important Exam Advice Important exam advice for sciences students. You cannot score marks unless you write answers but this does not mean you should spend all the time writing in an examination. It is important to read the question carefully so that you know what to answer. By knowing what needs to be covered, you …