warm-up: drops on a penny complete the mini-lab on your desk. write your answers on the paper...

32
Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book.

Upload: hannah-lewis

Post on 13-Dec-2015

223 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Warm-Up: Drops On A Penny

Complete the mini-lab on your desk. Write your answers on the paper provided and

glue sideways into your composition book.

Page 2: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Biology NotesBiology &

BiochemistryPart 3

Pages 40-43

Page 3: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Standard____ Discuss the properties of water that

contribute to Earth’s suitability as an environment for life: cohesive behavior, expansion upon freezing, and versatility as a solvent

Essential Question

2.1

How do the unique properties of waterallow life to exist on Earth?

Page 4: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

I. WaterWater is a molecule which means its atoms

__________ electrons

• This makes water a _____________ molecule

• In water, there is one atom of ___________ and two atoms of __________

share

covalent

oxygenhydrogen

Page 5: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Remember…..Compounds are made of atoms. Water has 3

atoms total. This makes water a compound. We know that the atoms share electrons but WHY???????

Compounds are formed so that atoms can get full outer energy shells

What is a full outer energy shell?

2 electrons on the first shell

8 electrons on the second shell

Page 6: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• Although the electrons in water are _________, they are not shared _________ between the oxygen atom and the ____ hydrogen atoms

polar molecule = a group of atoms that __________ electrons unequally resulting in charges on the atoms

water is a _______ covalent molecule

shared equally2

share

polar

Page 7: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• Due to it’s polarity, (unequal sharing of electrons) the oxygen atom in water has a small ________ charge and each of the hydrogen atoms has a small __________ charge

negativepositive

Page 8: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Drawing of water as a polar covalent molecule:

Page 9: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• The charges on a water __________ allow it to be attracted to and ________ with other water molecules

Hydrogen Bond = the bond that forms between hydrogen and another ________ covalent molecule

hydrogen bonds are considered to be very ______ and not nearly as strong as __________ or ionic bonds

moleculebond

polar

weakcovalent

Page 10: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book
Page 11: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• Water’s _________ and the resulting __________ bonds that water can form with itself as well as other _______ covalent molecules allows water to have very special _________

These properties explain why water is important to _______ on _______

polarityhydrogen

polar

properties

life Earth

Page 12: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

II. The Properties Of WaterA. Water is cohesive

• Cohesion = an attraction between ___________ of the same substance

• water is attracted and ______ to itself with weak __________ bonds

e.g.

molecules

hydrogen

water droplets,dew

bonds

Page 13: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

B. Water has surface tension

• Surface Tension = in bodies of water, the inward _____ of water molecules caused by _________

surface tension is the reason why certain bugs can ________ on water

pull

walk

cohesion

Page 14: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Drawing of surface tension in a pond or lake:

Page 15: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Think about it……

Why do oceans not exhibit surface tension?

Imagine we are all form a circle and have a sheet pulled tight on the edge. Still holding on we lean back. What happens if one person lets go?

Oceans do not exhibit surface tension because of currents, wind, and objects that break the hydrogen bonds between the water molecules.

Page 16: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

C. Water is adhesive• Adhesion = an attraction between molecules of

__________ substances

water is attracted to other ______ molecules

different

polar

Page 17: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Drawing of water in a glass showing adhesion:

Page 18: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

D. Water can move by capillary action

• Capillary Action = the ability of water to move ___ thin tubes even defying _________

capillary action is due

to ___________

e.g.

upgravity

adhesion

xylem in trees, paper towels

Page 19: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

E. Water is a universal solvent• Solution = a mixture of two or more

____________ in which molecules are distributed _________

i.e.

• Solvent = the substance in which the solute __________Due to water’s _________, solutes that are

also ________ are attracted to water and tend to break apart and become surrounded by the _________

e.g.

substancesevenly

sugar water / salt water

dissolves

polaritypolar

water

see page 42

Page 20: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book
Page 21: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• In the body, water is valuable as a solventwater dissolves ( _________

________ ) the foods we eatbreaks apart

Page 22: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Going back to oceans….Another reason why oceans do not display

surface tension is because of the salt….WHY?

Water is attracted to the salt more than itself so it’s water is less cohesive to itself. Without cohesion, there can be no surface tension.

Page 23: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

F. Water has a high heat of vaporization

• Heat of vaporization = the amount of _____ it takes for a substance to ___________

it takes a large amount of heat to _______ the hydrogen bonds between water molecules

heatevaporate

break

Page 24: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

this is valuable in the human body in the form of _______

when we exercise, heat accumulates in the _______

the heat is used to ___________ the water in the body

sweat results and _____________ is maintained for body temperature

sweat

body

evaporate

homeostasis

Page 25: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

III. Acids, Bases & pHIn some instances, when water is used to

dissolve substances, some of the water molecules will break down to form ions

(ion = an atom/compound that has gained or lost an electron forming an electrical charge on the atom/compound)

Page 26: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

Breakdown of water molecules to form ions:

____ = Hydrogen ion _____ = Hydroxide ion

We can determine how ______ or ______ a substance is by measuring the amount of __________ ions formed when that substance is dissolved in water

H2O → OH- + H+

OH-H+

acidic basic

hydrogen

Page 27: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• pH (potential of hydrogen) = the concentration (strength of amount) of ___ ions in solution (when the substance is dissolved in ______)

pH is measured of a sale of _________

A pH of ____ is considered neutral

A neutral solution is one that has an equal amount of ____ ions and ____ ions e.g.

H+

water

0 - 14

7

OH- H+

distilled (pure) water

Page 28: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book
Page 29: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• acid = a substance that forms ____ in solution and has a pH of ______

this means there are more ____ ions than ______ ions

e.g.

H+

0 - 6

H+

OH-

acid raintomato juicestomach acid

Page 30: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• base = a compound that forms ____ in solution and has a pH of ______

This means there are more ____ ions than ____ ions

e.g.

OH-

OH-

H+

8-14

alkaline batteriesdetergents

blood

Page 31: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book

• In the human body a pH between ___ and ___ must be maintained as part of _____________

buffer = a substance used to help __________ pH within the body

e.g.

6.57.5homeostasis

maintain

Tums, calcium, pepcid AC, milk of magnesia

Page 32: Warm-Up: Drops On A Penny Complete the mini-lab on your desk. Write your answers on the paper provided and glue sideways into your composition book