The sciences of physics and chemistry 65 Imagine you work in a lab and you have to analyse a rock sample. Which of these tests would you do in a physics lab? Which in a chemistry lab? a) Measure its mass. b) Measure its hardness. c) Analyse its composition. d) Determine whether it is affected by acid. e) Measure its density. 66 Imagine you work in your local environmental department. In your notebook, classify these situations as physical or chemical issues. a) Separating packaging according to the material it is made of. b) Reducing the size of packaging. c) Recycling glass packaging to make new glass packaging. d) Obtaining energy from plastic or cardboard packaging that cannot be recycled. 67 S C I E N C E A N D S U S TA I N A B L E D E V E L O P M E N T. Angela Merkel, Chancellor of Germany from 2005 to 2021, has a degree in Physics and a PhD in Chemistry. In 1998 she published an article in the Science journal, called The role of science in sustainable development, in which she stated: "The aim of sustainable development is both to protect the environment and achieve economic growth. This means not consuming resources faster than they can be regenerated, and not releasing more pollutants than natural resources can absorb. Science has an important role to play in achieving sustainable development [...], which can only succeed if all areas of politics, society and science work together." (Adapted) a) Find information about Angela Merkel and her professional biography. b) In your notebook, write what sustainable development means, according to Merkel. c) Explain, with examples, why science is important for sustainable development. d) Do you think it is important to have some people with a scientific background in the government? Give reasons for your answer. Measurements 68 Convert these amounts: a) 0.08 kg ® mg c) 548 dg ® hg b) 5.7 dag ® cg d) 37 mg ® kg 69 Order these amounts from largest to smallest: a) 254 cm b) 0.0003 km c) 8.2 dam 70 Order these amounts from largest to smallest: a) 8 456 cm2 b) 0.000 86 km2 c) 0.8 dam2 71 Convert these amounts: a) 7.5 dam3 ® L c) 0.000 65 km3 ® m3 b) 875 mL ® dm3 d) 378 dm3 ® L 72 Convert these amounts: a) 805 cL ® hL c) 2.5 L ® mL b) 0.35 dal ® dL d) 48 mL ® daL Measuring instruments 73 Look at the thermometers in the photos. One is used to measure air temperature. Another is used to measure body temperature. And the other is used to measure oven temperature. It is important to choose the right type of thermometer for the temperature range we want to measure. a) What are thermometers A, B and C used for? b) What unit does each thermometer measure in? c) One of the thermometers shows two temperature scales at the same time. Find on it the equivalent temperatures to those below. Write in your notebook: 0 °C ® °F 20 °C ® °F -5 °C ® °F 40 °C ® °F The precision or sensitivity of a device is the minimum quantity that it allows us to measure. Complete the table in your notebook. Precision or sensitivity Room thermometer … Medical thermometer … Oven thermometer … A B C 1 c h e c k yo u r p r o g r e s s 29
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