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Warm Up, October 24 th , 2013. Why does water stick to itself? Why does water stick to most other things? What do you think the term ‘surface tension’ means (as it relates to water)? Write the molecular formula for water and draw a water molecule. - PowerPoint PPT Presentation
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Warm Up, October 24th, 20131) Why does water stick to itself? Why does
water stick to most other things?2) What do you think the term ‘surface
tension’ means (as it relates to water)?3) Write the molecular formula for water and
draw a water molecule.4) Why is water special (other than ‘it
supports life’)
Pumpkin, Day ???
Pre-Assessment – Water 2Then Graphing old Pre and Post Water 1
GRAPHING SUCCESS (EXAMPLE)
Earth 1 Earth 2 Water 1 Water 20
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Pre-AssessPost-Assess
The Strange and Wonderful Mr. WaterWater is an interesting, very unique, and required material in your every day life.
But what makes water so great, you ask?
1. It DISSOLVES most stuff…eventually —UNIVERSAL SOLVENT
The Strange and Wonderful Mr. Water
1. It DISSOLVES most stuff…eventually —UNIVERSAL SOLVENT
2. It occurs NATURALLY in ALL 3 STATES of matter.
The Strange and Wonderful Mr. Water
SOLID liquid
gas
1. It DISSOLVES most stuff…eventually —UNIVERSAL SOLVENT
2. It occurs NATURALLY in ALL 3 STATES of matter.
3. It’s NECESSARY for LIFE!
The Strange and Wonderful Mr. Water
It’s NECESSARY for LIFE!
The Strange and Wonderful Mr. Water
1. It DISSOLVES most stuff…eventually —UNIVERSAL SOLVENT
2. It occurs NATURALLY in ALL 3 STATES of matter.
3. It’s NECESSARY for LIFE!4. Its SOLID form (ice) is LESS DENSE than its LIQUID form.
Why? Yeah I know that, but why?
The Strange and Wonderful Mr. Water
Short Chemistry Detour
So here’s a standard water molecule
OHH
Whose molecular formula is H2O
Short Chemistry Detour
This same water molecule had a positive side and a negative side.
OHH
And if you remember anything from 6th or 7th grade…
it should be magnets.
So, like magnets, and the Earth;
water has two poles.
Short Chemistry DetourSo based on that knowledge, how is water molecule
1 going to react to water molecule 2?
12
Short Chemistry DetourThe negative end is going to attract the positive
end and vice versa.
1
2
Because of this, we say water has polarity.
THEY ACT LIKE TINY MAGNETS.
Short Chemistry DetourNow, because water molecules act like tiny
magnets, very unique situations occur.
ADHESION COHESION
Adhesion, from adhere, verb - meaning: ‘stick
fast to (a surface or substance).’
Cohesion, containing prefix
co, - meaning: ‘together or
jointly’
Short Chemistry DetourNow, because water molecules act like tiny
magnets, very unique situations occur.
ADHESION COHESION
Water will stick to other stuff
and defy gravity.
Water will also stick to itself!
(polarity)
Short Chemistry DetourNow, because water molecules act like tiny
magnets, very unique situations occur.
ADHESION
Water will stick to other stuff and
defy gravity.
Example? Capillary action in plants!
Short Chemistry DetourNow, because water molecules act like tiny
magnets, very unique situations occur.
COHESION
Water will also stick to itself!
(polarity)
Think people cooperating!
Short Chemistry DetourNow, because water molecules act like tiny
magnets, very unique situations occur.
COHESION
Water will also stick to itself!
(polarity)
Also think, surface tension!
Short Chemistry DetourNow, because water molecules act like tiny
magnets, very unique situations occur.
This random bug can balance
on water, can you do the
same with an ordinary staple?
Do you even lift?
Short Chemistry DetourSo when water freezes, what happens and why
does water expand???