Bell ringer…

1. Bell ringer… • What is the chemical formula for water? Is it a compound, element, or a mixture? How do you know?

2. Movie clip.. • Brainstorm alone: Why does ice float? (1 minute) • Brainstorm with your partner: Each partner has 1 minute to share his/her idea! • Brainstorm as a class: 1 minute!

3. Why does ice float? • As ice freezes, it traps air between the molecules of water, which causes them to EXPAND. The trapped air bubbles makes the ice LESS DENSE than the liquid water, which causes it to float!

4. Interactive notebook.. • This is something we are going to do for the HYDROSPHERE UNIT! • You will need about 20 sheets of notebook paper and two pieces of construction paper. • The cover can be decorated however you want to! But you must have your name, your core, and my class name on it! • The first inside page is the “Index”. You MUST have your index completed when notebooks are checked.

5. You write notes, lab reports, and anything I GIVE YOU on the RIGHT SIDE OF THE PAGE! • Your DOWNLOAD page is the left side. This is where you will complete journal entries, illustrations, or anything else pertaining to what you learned on the right side!

6. Water Properties Unit 8.3: Goal 3

7. Properties of Water • Universal Solvent • Polarity • Adhesion • Cohesion • Density • Capillary Action • Surface Tension • Buoyancy

8. Universal Solvent • Water is considered the UNIVERSAL SOLVENT because it can dissolve almost anything. • EXAMPLE: • Water dissolving sugar. • Water dissolving salt. • Water dissolving alcohol.

9. Polarity • Uneven charges across a molecule. • Water has 2 Hydrogens and 1 Oxygen. The Hydrogens give their VALENCE ELECTRONS to the Oxygen. The HYDROGENS become POSITIVE and the Oxygen is NEGATIVE! (Remember: electrons are negative). • Because water is POLAR, it can dissolve almost anything (the positive H’s attract negative ions and the negative O attracts positive ions.

10. Adhesion • Water bonding to other substances. • EXAMPLE: • Water absorbing into a paper towel. • Water soaking into clothes. • Drops of water sticking to the side of a car after it rains.

11. Cohesion • Water molecules bonding together. • EXAMPLE: • Small water drops joining together to make large water drops. • Being able to “connect” water puddles.

12. Density • Water’s density is 1.0g/mL when it is LIQUID! • Ice floats on liquid water, so SOLID WATER is LESS DENSE than liquid water! • Just before water freezes, at 4C, water is its most dense. When it freezes, water traps air molecules between the molecules, which causes it to be less dense.

13. Capillary Action • The ability of water to “climb” up other surfaces. • EXAMPLE: • A plant soaking up water through its roots. • Water climbing up the side of a straw. • Using water and food coloring to change the color of flowers.

14. Surface Tension • The ability of water to make a rounded surface. This is a COHESIVE property. • EXAMPLE: • Being able to add water to a glass over the rim. • Continuously adding drops of water to a puddle. • Water spiders walking across the surface of water without sinking. • WHY “BELLY FLOPS” ARE PAINFUL!

15. Buoyancy • The upward force of water. • EXAMPLE: • Boats are more dense than water, but they float because of the buoyancy of water. • If you push a beach ball into the pool, it shoots back up because of the upward force of the water.

16. Which is this an example of?

17. What is this an example of?

18. Which property of water would this be?

19. What property is being shown here? Water on a penny.

20. Which property is being shown here? Water on a car window.

21. Which property is this? Ink dissolving.

22. Homework • On your left hand side, you are to explain each water property using a poem, song, or short story.