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Bell ringer

Bell ringer. Time Warp water droplets. Time Warp water droplets. KEY CONCEPT Water’s unique properties allow life to exist on Earth. FL NGSSS.

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Bell ringer

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  1. Bell ringer • Time Warp water droplets • Time Warp water droplets

  2. KEY CONCEPTWater’s unique properties allow life to exist on Earth.

  3. FL NGSSS • 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. ( Moderate)

  4. THE PROPERTIES OF WATER : Water has some very unique properties that make this molecule unlike ANY other. And we are made up of about 70% water!

  5. Your body is made up of mostly of water. Approximately 85% of your brain, 80% of your blood and 70% of your muscle is water. Every cell in your body needs water to live.

  6. _ O H H + + Life depends on hydrogen bonds in water. • Water is a polar molecule. • Polar molecules have slightly charged regions. • Nonpolar molecules do not have charged regions. • Hydrogen bonds is a weak bond form between • slightly positive hydrogen atoms and slightly negative • atoms. 3

  7. Hydrogen bonds are responsible for three important properties of water. large amount of energy needed to produce an increase in temperature • High specific heat- • Cohesion - water molecules • “stick” to each other • Adhesion - water molecules • “stick” to other substances 4

  8. Cohesion • Water’s tendency to cling together • Water in space When the negative end of a water molecule attracts the positive end of another water molecule, and the molecules stick together, this is called cohesion.

  9. Adhesion • Adhesion, or capillary action, is when water molecules are attracted to other substances with a negative or positive charges. This is why water "climbs" up a piece of paper or a straw above the surface level of the water.         This figure shows water adhesion

  10. Because of the cohesive properties of water, trees such as the giant sequoia are able to transport water molecules from the soil to their leaves 300 ft. above. WATER: STRONG COHESIVENESS 300 ft. Water molecule released into the atmosphere As each water molecule evaporates, it pulls additional water up through the tree because of the “sticky-ness” of the hydrogen bonds that link the water molecules. Water molecules pulled upward 6-ft.-tall man Water molecule pulled into root system

  11. Phloem and Xylem -Phloem-Transport sugars and molecules created by the plant. Transports food made during photosynthesis.Xylem-System of tubes in a plant that transport water and dissolved minerals. The xylem distributes the water throughout the plant.

  12. Trouble on the Surface Lab

  13. WATER: HIGH SURFACE TENSION Pressure applied to water surface Hydrogen bond “V”-shaped water molecules are held together by hydrogen bonds. The bonds are just strong enough to give water a surface tension with net-like properties.

  14. Surface Tension • The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. • The molecules at the surface do not have other like molecules on all sides of them and consequently they cohere more strongly to those directly associated with them on the surface. • This forms a surface "film" which makes it more difficult to move an object through the surface than to move it when it is completely submersed.

  15. Other unique properties of water • Only substance to that exists free in nature in all three states (solid, liquid, and gas) • High boiling point • Low freezing point • Viscosity increases as its temperature is lowered • A strong surface tension • A relatively high density to support animals with no or delicate skeletal systems • A high heat capacity which maintains relativity stable and slow changing internal temperature • Ability to dissolve most substances

  16. Universal Solvent Since unlike charges attract, the negative end of water will be attracted to the positive sodium ion. The positive end of water will be attracted to the negative chloride ion.Since water is always in motion, it will pull on the ionic compound and move the ions away from each other. This dissolves the ionic compound.

  17. solution Many compounds dissolve in water. • A solution is formed when one substance dissolves in another. • A solution is a homogeneous mixture. • Solvents dissolve other substances. • Solutes dissolve in a solvent. 5

  18. “Like dissolves like.” • Polar solvents dissolve polar solutes. • Nonpolar solvents dissolve nonpolar solutes. • Polar substances and • nonpolar substances generally remain separate. 6

  19. Common Misconceptions • Students often thinks that all solutes are solids and all solvent as are liquids. • Correcting the misconception • Solutions can involve different states of matter

  20. stomach acid pH between 1 and 3 more acidic Some compounds form acids or bases. • An acid releases a hydrogen ion when it dissolves in water. • high H+ concentration • pH less than 7 7

  21. bile pH between 8 and 9 more basic • A base removes hydrogen ions from a solution. • low H+ concentration • pH greater than 7 8

  22. pure water pH 7 • A neutral solution has a pH of 7. 9

  23. pH Scale

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