WOD: FETTER (FET ur) v./n. to restrain; to hamper; a shackle The prisoners were FETTERED by shackles around their ankles. The cowboy FETTERED his horse so it would still be there when he wanted to go home. The prisoner’s FETTER was attached 11/18 Chapter 7.1 Notes 34 Pg 7-15 #1-12 35 DO NOW 1.) Please find your folder from the stack located by the sink and place all passed back papers into your folder. 2.) Did your test score reflect the grade you predicted you would receive? Why or why not?

Chapter 7.1: The Physics of Water INB Pg 34

The Physics of Water Seawater’s chemical properties affect how life functions in the oceans. Water’s physical properties not only affect life processes of marine organisms, but of human beings in the water.

The Physics of Water Heat and Heat Capacity Heat is the kinetic energy in the random movement, or vibration, of individual atoms and molecules in a substance. The faster molecules move, the more heat there is. Total heat energy is measured based on both the quantity and speed of vibrating molecules. Temperature measures only how fast the molecules vibrate. The two most common temperature systems are Fahrenheit and Celsius. Celsius is most used in science because it is based on water’s physical properties. http://www.youtube.com/watch?v=wTi3Hn09OBs The Physics of Water Chapter 7 Pages 7-3 to 7-5

Heat and Heat Capacity (continued) Heat capacity of a substance is the amount of heat energy required to raise a given amount of a substance by a given temperature. Scientists express heat capacity in terms of the amount of heat energy it takes to change one gram of a substance by 1°C. It’s expressed as the number of calories required. It takes more heat energy to raise water’s temperature than that of most substances. Therefore water can absorb or release a lot of heat with little temperature change.

Heat and Heat Capacity (continued) Water’s heat capacity affects the world’s climate and weather. Heat is carried to areas that would otherwise be cooler, and heat is absorbed in areas that would otherwise be hotter.

Water Temperature and Density As water cools it becomes denser. At 3.98°C (39.16°F) it reaches maximum density. Below this point, it crystallizes into ice. As water moves into a solid state* it becomes less dense. * State is an expression of a substance’s form as it changes from solid, to liquid, to gas with the addition of heat.

Water Temperature and Density Ice does not form all at once at the freezing point of 0°C (32°F), but crystallizes continuously until all liquid turns solid. Temperature does not drop any further until all the liquid water freezes, even though heat continues to leave. This produces non-sensible heat – a change in heat energy that cannot be sensed with a thermometer. The non-sensible heat lost when water goes from liquid to solid state is called the latent heat of fusion. Sensible heat is that which you can sense with a thermometer.

Water Temperature and Density Latent Heat of Vaporization Latent heat of vaporization is the heat required to vaporize a substance. It takes more latent heat to vaporize water than to freeze it because when water freezes only some of the hydrogen bonds break. When it vaporizes, all the hydrogen bonds must break, which requires more energy.

Thermal Inertia The tendency of water to resist temperature change is called thermal inertia. Thermal equilibrium means water cools at about the same rate as it heats. These concepts are important to life and Earth’s climate because: Seawater acts as a global thermostat, preventing broad temperature swings. Temperature changes would be drastic between night and day and between summer and winter. Without the thermal inertia, many – perhaps most – of the organisms on Earth could not survive the drastic temperature changes that would occur each night.

Ocean Water Density Seawater density varies with salinity and temperature. This causes seawater to stratify, or form layers.

Ocean Water Density Dense water is heavy and sinks below less dense layers. The three commonly found density layers are: 1. Surface zone – varies in places from absent to 500 meters (1,640 feet). In general it extends from the top to about 100 meters (328 feet). This zone accounts for about only 2% of the ocean’s volume. 2. Thermocline – separates the surface zone from the deep zone. It only needs a temperature or salinity difference to exist. This zone makes up about 18% of the ocean’s volume. 3. Deep zone – lies below the thermocline. It is a very stable region of cold water beginning deeper than 1,000 meters (3,280 feet) in the middle latitudes, but is shallower in the polar regions. The deep zone makes up about 80% of the ocean’s volume.