August 24th , 2018 3. What is a hypothesis? FIRST FIVE CHECK Pick up materials. Find seat. Organize desk and materials. Write down homework. Begin DO NOW. August 24th , 2018 DO NOW #3 1. Identify which part of this phrase is an observation – “I saw ice on the lake yesterday. The lake must be cold.” 2. Identify which part of this phrase is an inference – “I saw ice on the lake yesterday. The lake must be cold.” 3. What is a hypothesis? 4. What makes something scientific? 5. How can being tardy impact your Do Now Grade? DO NOT TOUCH ANY LAB MATERIALS OR ELSE!!!!!!

DO NOW #3 Answers 1. Identify which part of this phrase is an observation – “I saw ice on the lake yesterday. The lake must be cold.” The part of the phrase that is an observation is “I saw ice on the lake” because it is a statement using one of the five the senses. 2. Identify which part of this phrase is an inference – “I saw ice on the lake yesterday. The lake must be cold.” The part of the phrase that is an inference is “the lake must be cold” because it is a guess or explanation based on your observations/knowledge.

DO NOW #3 Answers 3. What is a hypothesis? A hypothesis is a testable prediction. 4. What makes something scientific? CONPAT – Consistent, observable, Natural, predictable, Able to change, and testable. 5. How can being tardy impact your do now grade? If I am tardy my do now grade will automatically drop to a 75.

Verbal Drills 1. When I say independent variable you say… MANIPULATE 2. When I say dependent variable you say… MEASURE 3. Observations use your… FIVE SENSES 4. Science is… The process of inquiry. 5. What is our class motto? BE UNCOMMON 6. What are our class goals? 100% of students will surpass the district average on the EOC. 100% of students will mastery 75% of course standards.

Properties of Water 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.

Properties of Water Objective: Explain how the polarity of a water molecule contributes to its unique properties. Essential question: How are the unique properties of water contributed to polarity and hydrogen bonding?

Investigate Fill a clean, soap-free bowl with water. See if you can get 3 paper clips to float on top of the water. Keep the fourth paperclip out of the cup. What happens if you just drop it? How did you get them to float?

What is the Structure of a Water Molecule? 1. Water is composed of 1 oxygen atom and 2 hydrogen atoms. 2. The oxygen has a negative charge and the hydrogen has a positive charge. 3. The hydrogen atoms are always in the “ear” position. Draw this in your notes with the charges

A B D C Practice Which diagram of a water molecule is correct? Choose the answer AND explain why. A B C. Ears and correctly labeled charges D C

water is polar Polarity- The state of having 2 opposite ends water is polar Since opposites attract each other, the negative end of one oxygen atom will be near the positive ends of 2 hydrogen atoms O and H are bonded to form one water molecule with slightly (+) and (-) ends (polar covalent bonds) What else has a positive and negative end? When do we use the word polar? **** talk about polarity before the structure of water molecules!!!!

What is Hydrogen Bonding? The bond between the oxygen (O) and Hydrogen (H) atoms of different water molecules and other polar molecules The positive H is attracted to the negative O of other water molecules. Hydrogen bonds are weak allowing water to move and reform bonds often If H2O is the formula for water, what is the formula for ice? H2O cubed. 

Water is Special Due to its Polarity Water's polarity allows it to have special properties: dissolve other polar substances very easily When a polar substance is put in water, the positive ends of its molecules are attracted to the negative ends of the water molecules, and vice versa. The polarity of water allows water to form Hydrogen Bonds Hydrogen bonds cause other special properties.

Four Properties of Water Cohesive Behavior (cohesion & Adhesion) Ability to moderate temperature Expanding upon freezing (density) Universal solvent

1. Cohesive Behavior: Cohesion Water is highly cohesive Co= together ex: cooperate, covalent etc. “hesion”= to stick Cohesion is the attraction of water molecules to stick together Cohesion allows for water to have surface tension Word Dissection! Ex. Water striders don’t break the high surface tension of water, allowing them to stay on the surface

1. Cohesive Behavior: Adhesion Adhesion is the attraction of water molecules to another substance. Ad=another Adhesion allows for capillary action, which allows water to move against the force of gravity Word Dissection! How does water get to the top of the tree if I only watered the soil?

Practice with Adhesion & Cohesion (whiteboard) What property of water does this each picture represent? 1. 2. 3.

2. Ability to Moderate Temperature It takes a lot of energy to change the temperature of water. High heat capacity In the picture, what is going to heat up and cool down faster? Land or water?

3. Expanding Upon freezing Density is how tightly packed the atoms in a substance are 1. Objects with greater/more density will sink. 2. Objects with smaller/less density will float. As a solid (ice), water molecules spread out, leaving more space between them and decreasing the density. This is why ice floats!

4. Universal Solvent Water is called the universal solvent because it can dissolve almost anything Solvent: usually a liquid; dissolves the other substance Solute: usually a solid; what is being dissolved Solution: a homogeneous mixture (looks the same throughout); formed when one substance dissolves in another

Universal solvent Water is a great solvent because the positive and negative ends act like magnets that pull apart other substances like dissolves like, water dissolves other polar molecules We know that water dissolves sugar, but that it doesn’t dissolve oil. What can we conclude about the sugar and oil molecules?? Since water is polar and it dissolves sugar, the sugar molecule must be polar. Since water doesn’t dissolve oil, the oil molecule must be nonpolar

Solute Water as a Solvent O O O O O O O O O O O O O O H H H H H H H H

Why does water have these unique properties? Water molecules’ Structure!!! = Water is polar

Revisit the floating paperclip What property is causing them to float? What is allowing for that property to exist? Predict what will happen if you add soap to your cup Try floating a paper clip now that the water has soap in it. What happens?

Key Points The unique structure of the water molecule determines it’s unique properties. Polarity and Hydrogen Bonding allow for properties of water

https://www.youtube.com/watch?v=z5Vm56Pu4hU

Building Water Molecules Working with your table partner, read through the article and follow instructions to build water molecules. C- level 2 H- ask three before me A- build water molecules and then answer the discussion questions under your DO NOW. (do not write on sheet, it’s a class set!) M- remain seated in your assigned seat P- work with your partner to complete activity (17 min) Success!

Exit Ticket Clear your desk of everything but the paper with your Do Now & a writing utensil Title the back of the paper “Exit Ticket” Number 1 – 5 Answer essential question

Exit 1 1. WHAT TYPE OF BOND TAKES PLACE BETWEEN ADJACENT WATER MOLECULES? A. COVALENT BOND B. IONIC BOND C. HYDROGEN BOND D. WATER BOND

Exit 2 2. The ability for life to survive underneath a frozen lake is made possible by A. Ice being more dense than water B. Ice being less dense than water C. Ice being colder than water D. Ice being harder than water

Exit 3 3. Why is water such a great universal solvent? A. Because the positive and negative charges pull apart other molecules B. Because water in its solid state in denser than in the liquid state C. Because the hydrogen atoms on a water molecule have a positive charge D. Because water is considered non-polar.

Exit 4 A. Water expands as it freezes. 4. Water is essential for life. Its special properties make water the single most important molecule in plant life. Leaves are unable to absorb water during irrigation or during precipitation, and must depend on the root system of the plant to absorb the water. The xylem is the vascular tissue that moves the water from the root system to the leaves to ensure water is present to function as a reactant for the process of photosynthesis. The picture below shows the process of water moving from the roots to the leaves. Which of the following properties of water enables it to move from the roots to the leaves of plants? A. Water expands as it freezes. B. Water is an excellent solvent. C. Water exhibits cohesive behavior. D. Water is able to moderate temperature

Exit 5 5. The picture was taken from the banks of Lake Erie in the winter of 2014. You can see that the exterior of the lake is covered with ice, while the center portion is not. The ice that is found on the exterior of the lake is floating on the water below. Why does the ice float? a. Water expands as it freezes, allowing in small air bubbles, so it floats. b. Water expands as it freezes, making it less dense that liquid water, so it floats. c. When water freezes it becomes polar, and so it will not mix with the non- polar water. d. When water freezes it becomes non-polar, and so it will not mix with the polar water.