About Water Students’ Sheet Introduction Water covers 70% of Earth’s surface. Without it there would be no life on our planet. In plants, water: dissolves nutrients from the soil and carries them around the plant is one of the reactants in photosynthesis (the other is carbon dioxide) keeps stems, leaves and shoots rigid (plants wilt if they have insufficient water) evaporates from leaves, which also cools the leaves Activities Activity 1: Structure of water There are three states of matter for water: solid, liquid and gas. The smallest water particles in all of these states are water molecules. The only difference between the states if how the water molecules are arranged and move. Density of ice and water at different temperatures State Temperature / oC Density / g/cm3 Solid (ice) 0 0.917 Liquid (water) 1 1.000 Liquid (water) 4 1.000 Liquid 20 0.998 Liquid (water) 40 0.992 Liquid (water) 60 0.983 Liquid 80 0.972 Gas (water vapour) 100 0.0006 Before answering questions make sure you know how the simple particle model can be used to explain the differences between solids, liquids and gases. Questions 1. A molecule has the formula H2O. (a) Atoms of which elements are needed to make a water molecule? (b) How many of each are needed? 2. Compare the data for ice and water. (a) Which has the largest volume, 1.000 g of ice or 1 g of water? (b) What does this tell you the arrangement of water molecules in ice compared to water? 3. Plot a of the density of water against temperature. (a) Describe the shape of the graph.
About Water Students’ Sheet Introduction Water covers 70% of Earth’s surface. Without it there would be no life on our planet. In plants, water: dissolves nutrients from the soil and carries them around the plant is one of the reactants in photosynthesis (the other is carbon dioxide) keeps stems, leaves and shoots rigid (plants wilt if they have insufficient water) evaporates from leaves, which also cools the leaves Activities Activity 1: Structure of water There are three states of matter for water: solid, liquid and gas. The smallest water particles in all of these states are water molecules. The only difference between the states if how the water molecules are arranged and move. Density of ice and water at different temperatures State Temperature / oC Density / g/cm3 Solid (ice) 0 0.917 Liquid (water) 1 1.000 Liquid (water) 4 1.000 Liquid 20 0.998 Liquid (water) 40 0.992 Liquid (water) 60 0.983 Liquid 80 0.972 Gas (water vapour) 100 0.0006 Before answering questions make sure you know how the simple particle model can be used to explain the differences between solids, liquids and gases. Questions 1. A molecule has the formula H2O. (a) Atoms of which elements are needed to make a water molecule? (b) How many of each are needed? 2. Compare the data for ice and water. (a) Which has the largest volume, 1.000 g of ice or 1 g of water? (b) What does this tell you the arrangement of water molecules in ice compared to water? 3. Plot a of the density of water against temperature. (a) Describe the shape of the graph.
SAPS%20-%203%20About%20water%20-%20student%20sheet.docx