1) The reddish brown coat that covers each old iron nail is called __________. a) brass b) bronze c) rust d) cocoa 2) Which object can rust? a) Iron nail b) Wooden chopsticks c) Glass pane d) Plastic ruler 3) An iron nail exposed to rain water rusts after a few days. What causes the rusting of the nail? a) Presence of both air and water b) Presence of dry ice c) Presence of dry air d) Presence of oxygen-free water 4) Which is an effect of rusting on an iron pole? a) The iron pole becomes covered with a black coat. b) The iron pole becomes covered with brown mud. c) The iron pole becomes covered with a dirty, rough reddish brown coat. d) The iron pole becomes covered with a reddish brown paint. 5) An iron nail is placed into a test tube. Boiled water and oil are poured into the same test tube. The setup is left for a week. What is the observation after a week? a) The nail dissolves in water. b) The nail remains shiny. It does not turn rusty. c) There are holes in the nail. d) The nail becomes rusty. 6) Which will NOT happen to an iron rod that is left exposed to damp air for a few weeks? a) The iron rod becomes easily broken. b) The iron rod remains shiny and strong. c) The iron rod becomes coated with a reddish brown coat. d) The iron rod appears dirty, rough and dull. 7) How can you tell the difference between a rusty nail and a non-rusty nail? a) A rusty nail appears shiny while a non-rusty nail appears dull. b) A rusty nail has a smooth surface while a non-rusty nail has a rough surface. c) A rusty nail is coated with reddish brown coat while the non-rusty nail appears shiny. d) A rusty nail is stronger than a non-rusty nail. 8) An experiment is done to find the factors that cause rusting. What is the conclusion based on the observations? a) Oxygen-free water is needed for iron to rust. b) When both water and air are present, iron rusts. c) Dry air causes iron to rust. d) Water that does not contain air causes iron to rust.

Rusting of Materials (Year 5)

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