Warm Up, October 24 th , 2013

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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4

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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???