Beatty 14.1_METALS_(W1)_2023_Answers

1 Beatty Secondary School Science Department (Chemistry Unit) Chemistry 6092 Name: ___________________________________ ( ) Date: ________________ Class: 3E___ TOPIC: PROPERTIES AND USES OF METALS AND ALLOYS (WORKSHEET 1) Learning Objectives: (a) Describe the general physical properties of metals as solids having high melting and boiling points, malleable, good conductors of heat and electricity in terms of their structure. (b) Describe alloys as a mixture of a metal with another element, e.g. brass; stainless steel. (c) Identify representations of metals and alloys from diagrams of structures. (d) Explain why alloys have different physical properties to their constituent elements. (e) Describe steels as alloys which are a mixture of iron with carbon or other metals and how controlled use of these additives changes the properties of the iron, e.g. high carbon steels are strong but brittle whereas low carbon steels are softer and more easily shaped. (f) State the uses of mild steel, e.g. car bodies; machinery, and stainless steel, e.g. chemical plants; cutlery; surgical instruments. Multiple-Choice Questions 1 Layers of metal atoms can slide over each other. Which property is explained by this fact? A Most metals have high melting points. B Metals conduct electricity. C Most metals have high densities. D Metals are malleable. ( D ) 2 Which diagram best shows the structure of an alloy? ( B ) 3 Which alloy of iron is used in surgical instruments? A high carbon steel B low carbon steel C mild steel D stainless steel ( D ) 4 Which pair of elements cannot be used to form an alloy? A aluminium and magnesium B chlorine and sodium C copper and zinc D lead and tin ( B )

2 5 Which row correctly lists the uses of metals? stainless steel mild steel aluminium A galvanising car bodies soft can drinks B car bodies soft can drinks galvanising C soft can drinks aircraft bodies pipes in chemical plants D cutlery machinery aircraft bodies ( D ) 6 The composition of stainless steel is as shown below. What is element X? A carbon B copper C iron D zinc ( C ) 7 High carbon steel is used in manufacturing processes. 1 It is brittle. 2 It is malleable. 3 It is soft. 4 It is strong. Which properties does high carbon steel have? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 ( B ) 8 Magnalium is an alloy of aluminium (8 5 %) and magnesium (15 %). Some properties of magnalium are listed below. Which property of magnalium is not a reason for its use in the construction of aircraft? A It conducts electricity. B It is less dense than aluminium. C It is stronger than aluminium or magnesium. D The surface of the alloy is covered by a layer of aluminium oxide. (