8.1+Water+properties+.pptx

Earth and Space Science Unit 8 Earth’s Water Lesson 1: Properties of Water Unit 8 Lesson 1 The Strength of Water • Caves are large empty spaces underground that form as a result of natural weathering. These features in the Luray Caverns in Virginia are primarily made of limestone. 2 • They can...

Earth and Space Science Unit 8 Earth’s Water Lesson 1: Properties of Water Unit 8 Lesson 1 The Strength of Water • Caves are large empty spaces underground that form as a result of natural weathering. These features in the Luray Caverns in Virginia are primarily made of limestone. 2 • They can range from sea caves to magnificent cathedral-like spaces like the Luray Caverns in Virginia. Unit 8 Lesson 1 The Strength of Water • Limestone deposits that cling to the ceiling of a cave are called stalactites, while those that reach up from the cave floor are called stalagmites. The slow drip of water through the caves leads to unique formations. 3 • Because stalactites slowly grow toward the ground and stalagmites grow toward the ceiling, they sometimes join in the middle to form a new structure called a column. Unit 8 Lesson 1 The Strength of Water Hands-On Lab: Water Solubility • Dissolving is the process in which a solid becomes incorporated into a liquid. • The liquid that does the dissolving is called the solvent. The substance being dissolved is called the solute. • Solubility is a measure of how much solute will dissolve in a given amount of solvent under given conditions 4 Unit 8 Lesson 1 The Strength of Water • Compared to most other liquids, water is excellent at dissolving things and is often referred to as the universal solvent. • Water’s three atoms are not quite in a line. The positive and negative charges are centered in slightly different places, or poles, so water is said to be polar. Water is very effective at dissolving other polar molecules. • Water’s ability to dissolve many substances, especially polar substances, produces amazing features like those found in caves. • In the ocean, many of these molecules remain dissolved in water for thousands, even millions, of years. • The concentration of dissolved molecules in ocean water 5 is much higher than in fresh water, such as rivers and Unit 8 Lesson 1 The Strength of Ice • Rocks seem like indestructible objects, but many rocks exposed at Earth’s surface are riddled with cracks and fissures. Castell y Gwynt in Wales is a fractured rock that is a popular destination for mountain climbers. 6 • Though the rocks in the Castell y Gwynt may look as though they were pulled apart by some catastrophic event, their current condition is actually due to the action of water. Unit 8 Lesson 1 The Strength of Ice• Water is not only special because of its abilities to dissolve minerals and flow with enough kinetic energy to weather and erode rocks. • As water temperature dips below 4 °C (39 °F), something unusual happens. As water freezes, it expands. 7 • The water molecules move farther apart. Then, as water reaches its freezing point, the water molecules reconfigure themselves to form a crystal, which forces the molecules farther apart. • The frozen water expands to become 9% larger than the Unit 8 Lesson 1 The Strength of Ice • Similar to how water expands in a cup, water also expands when it seeps into cracks in rocks. It enters the rock in its liquid form and freezes when temperatures dip below 0 °C. Bryce Canyon National Park 8 • As the ice expands, it forces the crack in the rock apart in a process called frost wedging. When the temperature increases, the ice thaws, returning to the liquid state. Unit 8 Lesson 1 Unique Properties of Water • Some regions of the country experience unusually large and frequent snowstorms. • Cities on the shores of lakes receive some of the heaviest snowfalls in all of the United States. Winter winds move across Lakes Superior and Michigan. 9 • Some cities such as Cleveland, Ohio, have been known to experience snowfalls as large as 178 cm from a single winter Unit 8 Lesson 1 Unique Properties of Water • Though Chicago and Lake Michigan experienced nearly the same atmospheric temperatures in 2015, their temperatures changed at different speeds. • As can be seen in the Mean Monthly Temperature graph, Chicago warms up and cools down faster than Lake Michigan does. • This results from the difference in the ways water and land store energy. • Specific heat is a property of a substance that describes the amount of energy required to raise its temperature. •10 Water requires more energy to change its