C 3 Chemicals in Our Lives – Risks & Benefits

1. C3 Chemicals in Our Lives – Risks & Benefits Lesson 2: Useful Rocks

2. Objectives • MUSTexplain how resources in the Earth were formed • SHOULD explain how geologists discover how rocks were formed • COULD explain how the development of the chemical industry depended on resources being available nearby

3. KeyWords • You need to be able to define the following: • Sediment • Sedimentary rock • Eroded • Dissolved • Evaporated

4. Textbook Answers 1) a) Coal, limestone, salt; b) Easy to transport to the factories. 2)Sedimentation – limestone and coal; evaporation – salt; mountain building – limestone; dissolving – salt; erosion – limestone. 3) Coal was formed in hot tropical climates; salt was formed when climates turned hot and dry. 4) a) Contains small, smooth grains of wind-blown sand. b) Made up of shells of animals that lived in the sea and contains other fossil sea creatures; there may be ripples showing that the rock was formed on the bed of rivers or the sea.

5. Worksheet Answers Activity 1 (Low demand) 1) Coal – burning in steam engines; limestone – building and farming; salt – flavouring and preserving food. Activity 2 (Standard demand) 1) Rock cycle diagram; coal – sedimentation and compression; limestone – sedimentation, compression, uplift, weathering, erosion; salt – dissolving, evaporation, compression. 2) Moved through different climates; which resulted in different rocks being laid down.

6. Worksheet Answers Activity 3 (High demand) 1) Contains small, rounded grains. 2) Waves when the sediment lay at the bottom of a river or sea. 3) The age of the rock; the conditions in which the rock formed; the climate at the time.