Uddingston Grammar School CfE Higher Chemistry Unit 1: Chemical Changes and Structure Sub-Topic C: Structure and Bonding Homework 5: Elements 1-20 Bonding and Structure 1. Which of the following elements exists as discrete molecules? A B C D Neon Carbon (diamond) Silicon Phosphorus 2. Which of the following structures is never found in compounds? A B C D Ionic Monatomic Covalent network Covalent molecular 3. Which of the following does not contain covalent bonds? A B C D Chlorine gas Argon gas Oxygen gas Carbon ( fullerene ) 4. Diamond has A B C D an ionic lattice structure a covalent network structure covalent molecules linked by London dispersion forces covalent sheets with only London dispersion forces acting between sheets 5. Which type of bonding is never found in elements? A B C D Metallic London dispersion forces Polar covalent Non-polar covalent 1 Uddingston Grammar School 6. Element X was found to have the following properties. (i) It does not conduct electricity when solid. (ii) It forms a gaseous oxide. (iii) It is a solid at room temperature. Element X could be A magnesium B silicon C nitrogen D sulphur 7. What type of bonding and structure is found in a fullerene? A B C D Ionic molecular Metallic network Covalent network Covalent molecular 8. At room temperature, a solid substance was shown to have a lattice consisting of positively charged ions and delocalised outer electrons. The substance could be A B C D diamond potassium mercury sulphur 9. Which of the following elements is most likely to have a metallic lattice structure? 2 Uddingston Grammar School 10. Which of the following elements exists as a covalent network ? A B C D Neon Sulphur Silicon Phosphorus 11. Information about four elements from the third period of the Periodic Table is shown in the table. (a) Complete the table to show the bonding and structure for each element. 2 (b) Why is there a decrease in the size of atoms across the period from aluminium to sulphur? 1 (c) Argon is also in the third period. Argon is a very useful gas and each year 750 000 tonnes of argon are extracted from liquid air. (i) Suggest how argon could be extracted from liquid air. 1 (ii) Air contains 1·3% argon by mass. Calculate the mass of liquid air needed to obtain 750 000 tonnes of argon. 1 (iii) Argon is used in the manufacture of magnesium powder. A jet of liquid argon is blown at a stream of molten magnesium producing fine droplets of metal. These cool to form the powder. Why can liquid air not be used to make magnesium powder? 1 (iv) Argon was discovered in 1890’s when samples of nitrogen prepared by different methods were compared. The element name was derived from the Greek argos, which means “lazy one”. 3 Uddingston Grammar School (v) Two samples of nitrogen can be prepared as shown. Method 1 Removing carbon dioxide and oxygen from the air. Method 2 Reaction of sodium nitrite with ammonium chloride. Using your knowledge of chemistry, comment on the discovery and naming of argon. 3 4 Uddingston Grammar School 12. Copy and complete the table below by adding the name of an element for each of the types of bonding and structure described. 2 13. The elements in the second row of the Periodic Table are shown below. Li a) Be B C N O F Ne Why does first ionisation energy increase on crossing the period from lithium to neon? 1 b) Diamond and graphite are forms of carbon that exist as network solids. Name a form of carbon that exists as discrete molecules. 1 c) Use the electronegativity values to explain why nitrogen chloride contains pure covalent bonds. 1 d) Name the element which would be described as having a monatomic structure. 1 TOTAL: 25 MARKS 5