Surname Centre No. Initial(s) Paper Reference 4 3 3 5 Candidate No. 2 H Signature Paper Reference(s) 4335/2H Examiner’s use only London Examinations IGCSE Team Leader’s use only Chemistry Paper 2H Higher Tier Tuesday 6 November 2007 – Morning Time: 2 hours Question Leave Number Blank 1 2 3 4 5 Materials required for examination Nil Items included with question papers Nil 6 7 8 9 Instructions to Candidates In the boxes above‚ write your centre number‚ candidate number‚ your surname
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Lijser‚ 2011 T opic A 1 : S tructure and Bonding The Periodic Table The nucleus contains positively charged protons and uncharged neutrons. The electron cloud is composed of negatively charged electrons. Elements in the same row are similar in size. Elements in the same column have similar electronic and chemical properties. An s orbital has a sphere of electron density and is lower in energy than the other orbitals of the same shell. A p orbital has a dumbbell shape and contains a node
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Approximately 15 short answer questions‚ most broken down into smaller parts. This is often an eclectic‚ unpredictable mix of questions from various units‚ and may demand students write short paragraphs‚ use equations and reference tables‚ or draw graphs and diagrams in order to correctly answer the questions. Students taking the exam should come with a 4-function or scientific calculator (not a graphing calculator)‚ pen‚ and pencil. Reference Tables will be provided. Students are required to stay
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properties: This is connected to the effect of the electric field of the ligands on the metal d orbitals and the electrons in them. This effect is a repulsion‚ so it does not explain the bonding. But‚ it does explain the d orbital energies in a complex. In what follows‚ we concentrate on the second component only. © Drs. XO‚ PHB‚ CWR Octahedral Ligand Field (10.3.1 too detailed) Any electron in a d orbital is repelled by the ligand lone pairs (like charges…) and therefore has its energy increased
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Subject Content Most of the objectives specified in this section relate to Knowledge with Understanding‚ although some indication has been given as to where the skills of Handling Information and Solving Problems may be developed. Teachers are reminded that‚ in the written papers‚ 40% of the marks are allocated to these higher ’thinking’ skills. In almost every section‚ students should therefore be given practice at dealing with unfamiliar situations so that these higher thinking skills can be developed
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review some basic chemistry. Planning Your Study You may find this time grid helpful in planning when and how you will work through this lesson. Suggested Timing for This Lesson (Hours) Chemistry Basics ¾ Radioisotopes ¾ Chemical Bonding 1 Types of Biochemical Reactions 1 Key Questions 1 What You Will Learn After completing this lesson‚ you will be able to • use appropriate terminology related to biochemistry • identify and describe the four main types of biochemical
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1. The diagram below shows the electronic structure of boron. (a) The electrons are represented by arrows. What property of the electrons do these ‘up’ and ‘down’ arrows represent? ..................................................................................................................................... (1) (b) Suggest why electrons which occupy the 2p sub-levels have a higher energy than electrons in the 2s sub-level. .....................................................
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p IB DIPLOMA PROGRAMME PROGRAMME DU DIPLÔME DU BI PROGRAMA DEL DIPLOMA DEL BI Chemistry Higher level and standard level Specimen paper 1s‚ 2s and 3s For first examinations in 2009 CONTENTS Chemistry higher level paper 1 specimen paper Chemistry higher level paper 1 specimen markscheme Chemistry higher level paper 2 specimen paper Chemistry higher level paper 2 specimen markscheme Chemistry higher level paper 3 specimen paper Chemistry higher level paper 3 specimen markscheme
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all Biological compounds. Without them‚ life on this planet as we know it could not exist. Due to the bonding possibilities between and among these elements‚ literally millions of organic compounds are possible. Carbon is the backbone of all organic compounds. It forms the main structure of the molecule with Hydrogen‚ Nitrogen‚ Oxygen and occasionally other elements replacing Carbon or bonding to it at key points in the molecular structure. A carbon skeleton is the basis of all amino acids and
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COrdination compounds Question 9.1: Explain the bonding in coordination compounds in terms of Werner’s postulates. =Werner’s postulates explain the bonding in coordination compounds as follows: (i) A metal exhibits two types of valencies namely‚ primary and secondary valencies. Primary valencies are satisfied by negative ions while secondary valencies are satisfied by both negative and neutral ions. (In modern terminology‚ the primary valency corresponds to the oxidation number of the metal
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