Bellringer Question The special properties of water make it the single most important molecule for living organisms. Which of the following properties of water allows solid water to be less dense than liquid water? A. Water expands as it freezes. B. Water is an excellent solvent. C. Water exhibits cohesive behavior. D. Water is able to moderate temperatures. Follow your classroom rituals and routines for bell ringers. Question will be answered at the end. Circulate throughout class to quickly check for responses.

Interactive Journal Entry “Properties of Water SC.912.L.18.12” Left Side Right Side Concept Map Guided Notes (Note: when copying reduce size to 67% to fit in composition books; students can staple/tape it in landscape format) Graphic Organizer Property of Water Parts One and Two Concept map and graphic organizer are available as separate documents. Direct students to take notes/examples in the boxes below the headings.

Properties of Water SC.912.L.18.12 - Discuss the special properties of water that contribute to Earth's suitability as an environment for life: cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent. Introductory Slide

Polarity Polarity is not one of the properties listed in the standard, but it allows all those properties to exist by causing Hydrogen bonding. Water is a polar molecule. It has a slight (-) charge on the Oxygen end and a slight (+) charge on the Hydrogen end. Students should be filling in their right side graphic organizer for slides 4-11

Hydrogen Bonding Hydrogen bonding is not one of the properties of water mentioned in the standard, but it allows those properties of water to exist. In water, there is an attraction between the (+) charged Hydrogen atom from one H2O molecule and the (-) charged Oxygen atom from another H20 molecule. Students should be filling in their right side graphic organizer for slides 4-11

Hydrogen Bonding Students should be filling in their right side graphic organizer for slides 4-11

Properties of Water 1. Exhibits Cohesive Behavior Cohesion is the attraction among like molecules of a substance. Hydrogen bonds make water molecules stick to each other. Example: Water beading up on a washed car. It also causes surface tension which allows paper clips to float on water. Students should be filling in their right side graphic organizer for slides 4-11

Adhesion Adhesion is not one of the properties of water listed in the standard, but works with cohesion in many instances. Adhesion is the attraction of water molecules to different substances. Example: Dew forming on the grass. Students should be filling in their right side graphic organizer for slides 4-11

Properties of Water 2. Ability to Moderate Temperature Hydrogen bonding gives water a high specific heat, which means that water resists changes in temperature. Example: If you put 100mL’s of alcohol and 100mL’s of water on a hot plate at the same heat setting, the alcohol would boil first. It has a lower specific heat. It is Important in cell temperature regulation because water absorbs heat released by cellular activity. Students should be filling in their right side graphic organizer for slides 4-11

Property of Water 3. Expansion Upon Freezing Unlike most substances, water expands upon freezing. Solid water (ice) is less dense than liquid water, allowing ice to float. Students should be filling in their right side graphic organizer for slides 4-11

Properties of Water 4. Versatility as a Solvent Many substances in living organisms dissolve in water. Solute – substance dissolved in a solvent to form a solution. Solvent – fluid that dissolves solutes in a solution. Example: Sweet Tea – Water is the solvent – Tea and Sugar are the solutes. Students should be filling in their right side graphic organizer for slides 4-11

Water is essential for life on Earth Single most abundant compound in living organisms. Universal solvent – allows for blood to be a solution. Students should be filling in their right side graphic organizer for slides 4-11

Bellringer Question The special properties of water make it the single most important molecule for living organisms. Which of the following properties of water allows solid water to be less dense than liquid water? A. Water expands as it freezes. B. Water is an excellent solvent. C. Water exhibits cohesive behavior. D. Water is able to moderate temperatures. Allow for students to change their answer, if needed.

Bellringer Question The special properties of water make it the single most important molecule for living organisms. Which of the following properties of water allows solid water to be less dense than liquid water? A. Water expands as it freezes. B. Water is an excellent solvent. C. Water exhibits cohesive behavior. D. Water is able to moderate temperatures. Discuss why A is the correct answer and why B, C, or D would not be the correct answer.

You Do Questions The following questions can be projected when an instructor reaches the “You Do” portion of the lesson or the handout can be used. Follow your classroom rituals and routines for student completion of the You Do portion of the lesson.

Large bodies of water, such as the Atlantic Ocean, do not quickly fluctuate in temperature. What is the reason for this phenomenon? A. Water expands as it freezes. B. Water is a versatile solvent. C. Water has a high specific heat. D. Water exhibits cohesive behavior.

2. The special properties of water. make it the single most important 2. The special properties of water make it the single most important molecule for living organisms. Which of the following properties of water allows solid water to be less dense than liquid water? A. Water expands as it freezes. B. Water is a versatile solvent. C. Water has a high specific heat. D. Water exhibits cohesive behavior.

The picture below shows an Olympic swimmer above the water, but still being covered with a thin layer of water. What property allows this to occur? Water expands as it freezes. Water is a versatile solvent. Water has a high specific heat. Water exhibits cohesive behavior.