1. Compare the atoms Li, Na, and K. Which atom is most reac - PowerPoint Presentation

Slide1

1. Compare the atoms Li, Na, and K. Which atom is most reactive? Explain your reasoning.2. They are 25 common elements essential to human life. These elements are also essential to other organisms. What does this say about the similarityamong organisms?3. What bond allows water to behave the way it does?

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3/13 Daily Catalyst Pg. 92 WaterSlide2

1. Compare the atoms Li, Na, and K. Which atom is most reactive? Explain your reasoning.

K, Valence electrons are further away from the nucleus2. They are 25 common elements

essential to human life. These elements are also essential to other organisms. What does this say about the similarityamong organisms?Since elements are similar, this suggest that organisms share an evolutionary background and require certain molecules for survival.3.

Describe

which property(s) allows water to move in a tree.

Hydrogen bonds

2

3/13

Daily Catalyst AnswersSlide3

Grades are due today!Grade check in at lunch or after schoolI will email you before I submit the gradesPlease review water over the weekend!33/13 Pg. 92 WaterSlide4

How many times can you subtract the number 5 from 25?

Only once, then you are subtracting it from 20, etc.

3/13 Brain TeaserSlide5

Daily CatalystClass BusinessObjectiveWater notes Quiz #23Homework: page 57: 1, 2,3, 5, 6, and read and outline page. 58-59 on notebook page 945

3/13 AgendaSlide6

Unit

9:

Chemistry

WaterSlide7

Today and tomorrow we will review basic chemistry and vocabulary to be able to apply these basic chemistry principles to advanced biology concepts.3/13 ObjectiveSlide8

Blue Book-Chapter 2# 2, 6, and 10Homework: read 3.2Cohesion- AnthonyHeat and temperature- TeresaWaters specific

heat-Tiffany and Bristin

Evaporative cooling-Tiana and DaquineInsulation of bodies of water- John and GianniThe solvent of

life- Kordell

Hydrophobic and hydrophilic

substances-Annie

Solute concentration in aqueous solutions – Mrs. Ireland and Daniel

Concept check 3.2 question

1--Erica

Concept check 3.2 question

2-Quinshelle

Concept check 3.2 question

3-Kiandria

Concept check 3.2 question

4-Taylor

Practice ProblemsSlide9

Water: The molecule that supports life on this planet!9

Water is the biological medium for all life on Earth

All living organisms require water more than any other substanceSlide10

Water: The molecule that supports life on this planet!10

Most cells are surrounded by water, and cells themselves are about 70–95% waterThe abundance of water is the main reason the Earth is habitableSlide11

Water: The molecule that supports life on this planet!11

Key Point #1:

Covalent bonds hold hydrogen to oxygen (STRONG!!!)Water is polare’s spend more time with oxygen (hogger)Difference in charges

Multiple water molecules are held together by h-bondsSlide12

Why is it unlikely that two neighboring water molecules would be arranged like this?12Stop… and think!O

H

H

H

HSlide13

Water has 4 essential properties13Key Point #2: Water’s properties:C

ohesive behaviorA

bility to moderate temperatureExpansion upon freezingV

ersatility

as a solventSlide14

1. Water’s cohesive & adhesive behaviorToothpick videohttp://www.wimp.com/toothpickswater/14Slide15

AnthonyKey Point #3: 15Slide16

Cohesion is when water molecules stick to each other.Due to hydrogen bonding16

CohesionSlide17

What causes water molecules to both cohere and adhere?17Yep! Our good buddy-

hydrogen bonding Cohesion is when water molecules stick to each other.

Adhesion is when water molecules stick to some other type of substance like plant cell walls.

Animation by scrolling over imageSlide18

What causes water molecules to both cohere and adhere?18Surface tension is a measure of how hard it is to break the surface of a liquid.

Surface tension is a consequence of cohesion. What causes it? Go ahead, guess!

Hydrogen bonding, yet again!Slide19

2. Water’s ability to moderate temperatureTeresaKey point #4:19Slide20

Anything that moves has kinetic energy (energy of motion).The faster a molecule moves, the greater its kinetic energy!Molecules will give off HEAT!Temperature is measuring the about heat given off20How does water

moderate temperature?Slide21

When two objects are brought in contact with one another, heat passes from the warmer to the cooler object until the two objects are the same temperature.21Slide22

How does water moderate temperature?22

Water has a high heat capacity. Heat capacity is the amount of heat required to raise 1 gram of water

by 1o Celsius (1 calorie = 4.184 J)What does that mean? It means water can absorb large quantities of heat without much change in its own temperature, thus it’s a good thermo regulator.But, why? Go, ahead…guess!Slide23

How does water moderate temperature?23

Yep! Hydrogen bonding again! The fact that each water molecule can make TWO H-bonds each means they are

really, really attracted to each other, thus more ENERGY must be added to the water sample to increase their molecular motion. Slide24

How does water moderate temperature?24

We should also discuss this effect as it relates to “air” with regard to the amount of water vapor in the air or humidity. The more water vapor in the air, the more heat the air can absorb.

Large bodies of water absorb heat from warmer air and release stored heat to cooler air. Slide25

Tiffany and BristinHigh specific heatKey Point #525Slide26

It’s a 2-way street! 26Water’s high specific heat can be traced to hydrogen bonding Heat

is absorbed when hydrogen bonds breakHeat is released when hydrogen bonds form

The high specific heat of water minimizes temperature fluctuations to within limits that permit lifeSlide27

Tiana and DaquineEvaporative CoolingKey Point #6:27Slide28

Care to examine some data?28Formulate an explanation for the temperature data presented below. Your explanation should address the properties of water as they relate to thermoregulation.Slide29

Ever sweat? Ever perspire? 29Evaporation is transformation of a substance from liquid to vapor

As a liquid evaporates, its remaining surface cools, a process called evaporative cooling Evaporative cooling of water helps stabilize temperatures in organisms

(sweating, panting, etc.)and bodies of waterSlide30

DISCUSS the following questions with a classmate:What are the 4 properties of water?What makes all of these properties, thus far, possible?How is waters ability to moderate temperature important to weather/climate?How are adhesion and cohesion different but important?What gives elements their personality? Reactivity?3/16 Daily CatalystSlide31

Monday: water and pH and quiz #23Tuesday: MacromoleculesWednesday: Protein and protein foldingThursday: finish up and workbook pagesFriday: Quiz #24 (mini-test on Chemistry)3/16 Class Business Pg. 92 Water Slide32

Daily CatalystClass BusinessFinish waterpHQuiz #23Homework: read about the macromoleculesProtein:Carbs:Fats:Nucleic acids:

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3/16 Agenda Pg. 92 Water Slide33

Insulation of bodies of water- John and GianniKey Point #7:3. Water’s expansion upon freezing33Slide34

Water is a freak! It expands upon freezing!34

Ice: stable hydrogen bonds

Liquid water: transient

hydrogen bondsSlide35

Water is a freak! It expands upon freezing!35

Ice floats in liquid water because hydrogen bonds in ice are more “

ordered” Water reaches its greatest density at

4°C, which is excellent news if you’re a fish!

If ice sank, all bodies of water would eventually freeze solid, making life impossible on EarthSlide36

Water is a freak! It expands upon freezing!36

Hydrogen bond

Ice:

Hydrogen bonds

are stable

Liquid water:

Hydrogen bonds

break and re-formSlide37

The solvent of life- KordellKey Point #8:4. Water’s Versatility as a Solvent37Slide38

Water’s Versatility as a Solvent38A

solution is a liquid that is a homogeneous mixture of

substancesA solvent

is the dissolving agent of a

solution or “dissolver”

The

solute

is the substance that is

dissolved or “

disolvee

”

An

aqueous solution

is one in which water is the solvent Slide39

Water’s Versatility as a Solvent39Water is a versatile solvent due to its polarity, which allows it to form hydrogen bonds

easily.Slide40

Water’s Versatility as a Solvent40Water can also dissolve compounds made of nonionic polar molecules

Even large polar molecules such as proteins can dissolve in water if they have ionic and polar regionsSlide41

Key Point #9: Hydrophobic and hydrophilic substances-Annie41Slide42

Hydrophilic vs. Hydrophobic42A

hydrophilic substance is one that has an affinity for water

A hydrophobic substance is one that does not have an affinity for water; “fears water”

Oil molecules are hydrophobic because they have relatively nonpolar bonds

A

colloid

is a stable suspension of fine particles in a

liquid (like milk—fat suspended in water—Yummy!)Slide43

Key Point #10: Solute concentration in aqueous solutions – Mrs. Ireland and Daniel43Slide44

Biological chemistry us “wet” chemistry. Most of the chemical reactions in organisms involve solutes dissolved in water. We need to know how many atoms and molecules are involved in reactions44Solute Concentration in aqueous solutionsSlide45

Concept check 3.2 question 1--EricaConcept check 3.2 question 2-QuinshelleConcept check 3.2 question 3-KiandriaConcept check 3.2 question 4-Taylor45Slide46

46Pg. 93 pHSlide47

Acids, Bases and Buffers. Oh, my!47ACIDIC AND BASIC CONDITIONS AFFECT LIVING ORGANISMSSlide48

Acids, Bases and Buffers. Oh, my!48Simply put,

Key Point #1: Acid

A substance that increases the H+

Key point #2: Base

A substance

that reduces the H

+

amount or increases the

OH-

Key point #3: Dissociation

To separate

BleachSlide49

Acids, Bases and Buffers. Oh, my!49Key point #4:

In water= Concentrations

of H+ and OH– are equal

Adding acids= adding H+

Adding bases= adding OH-

Biologists use something called the pH scale to describe whether a solution is acidic or basic (the opposite of

acidic; also known as alkaline)Slide50

The pH Scale50The scale was designed to compare acids and bases.Slide51

Key Point #5: The pH Scale51

Acidic: 0-7

Basic: 8-14

Neutral: 7

Water?

Blood?Slide52

Acids, Bases and Buffers. Oh, my!52Key Point #6: Buffers

The internal pH of most living cells must remain close to pH 7

Buffers are substances that RESIST changes in concentrations of H

+

and OH

–

in a solutionSlide53

Buffers in Action53Human activities such as burning fossil fuels threaten water quality

CO

2 is the main product of fossil fuel combustionAbout 25% of human-generated CO2

is absorbed by the oceans

CO

2

dissolved in sea water forms carbonic acid; this process is called ocean acidification

Acidification: A Threat to Water QualitySlide54

Buffers in Action54As seawater acidifies, H

+ ions combine with carbonate ions to produce

bicarbonateCarbonate is required for calcification (production of calcium carbonate) by many marine organisms, including reef-building coralsSlide55

Acid Rain55The burning of fossil fuels is also a major source of sulfur oxides

(SO

x) and nitrogen oxides (

NO

x

)

These “socks and knocks” compounds

react with water in the air to form strong acids that fall

within

rain or snow

Acid precipitation

is rain, fog, or snow with a pH lower than 5.2

Acid precipitation damages life in lakes and streams and changes soil chemistry on land Slide56

Acid Rain: Before & After56Slide57

Quiz #2357