Water wrap up

Thursday September 12th

 Which statement BEST describes an effect of the low density of frozen water in a lake?

A.  When water freezes, in contracts, decreasing the water level in a lake.

B.  Water in a lake freezes from the bottom up, killing most aquatic organisms.

C.  When water in a lake freezes, it floats, providing insulation for organisms below.*** Remember we discussed how lakes do NOT freeze from the bottom up.  If they did most of the marine life in that lake/pond would die off every year!!!

D.  Water removes thermal energy from the land around a lake, causing the lake to freeze.

 

Before we took our open notes quiz I had you watch the following crash course and instructed you to pull out 5 terms he discussed, jot them down, and then write a statement about each term and how it applies to our study of water.

 

We then took our open notes quiz!!  Tomorrow =  Daily Question Quiz!!!!

specific heat and water as a solvent

Wednesday September 11^th

 

Water will form hydrogen bonds with other substances such as glass, soil and plant tissues. The term for this type of attraction is known as Adhesion

A combination of this and Cohesion can cause water to ‘defy gravity’ by moving UP narrow tubes (such as the roots of trees) in a process known as Capillary Action

**

Water is able to resist drastic changes in temperature because it has a high Specific Heat (heat capacity)

Why is this important to us? (As humans)
We are made up of approximately 75% water as is the EARTH..... We rely on waters ability to store large amounts of heat in order for our planet to remain a livable temperature!!

Speaking of heat capacity..... Today was another brutal hot day, so you guys got to take it RELATIVELY easy.  We just discussed specific heat again, moved into the importance of water being LESS dense as a solid than a liquid, and finally about how water is a great solvent.  Here were the notes from Wednesday.

 

Adhesion and capillary action activity and notes

Tuesday September 10^th 

*Water can and WANTS to form bonds with how many other water molecules? 4 (EVERY water molecule wants to bind with 4 others so it will eventually form a crystal like structure like this.

*Waters attraction to other water molecules is known as Cohesion 

*The term for how water “pulls in” at the surface to form a “film” is known as Surface Tension (Which we saw yesterday)

A water molecule is a polar molecule used in all living organisms. 

 

Which process is the direct result of the polarity of the water?

A.  The storage of chemical energy

B.  The destruction of damaged cell parts

C.  The transferring of genetic information

D.  The dissolving of a variety of substances

 

 

We then looked at Adhesion and capillary action today with the following notes and activities.

 Here is a poor quality video of how we viewed capillary action (pay no attention to the sound ;)

 

 

Wonders of water day 2 and 3

Friday we had our daily question quiz and then started into more water labs.

First you filled your jars ALL the way to the top with water

Then you added enough water so that the level was slightly higher
than the rim of the jar.

Then we started adding pennies!!

One at a time you added pennies to your already full jar of water to see how many you could get in there before it overflowed.

Many of you were able to get quite a few pennies in there before it started to actually over flow!!!

Now to see what all of this means... we started into how water binds with other water molecules.

 

Using the models in your cups – make 5 water molecules then place how you think one would bond with 4 others.

 

What type of bond holds two water molecules together?
Hydrogen Bonds
 

Today we continued with notes and activities on Water.  First refreshing our knowledge of the structure of water and how it bonds with others using two slides from Friday (See above).  Then we moved on into Cohesion.

 

 
Next demo was to show cohesion and surface tension using pennies.


Using a Pipette, we added as many drops of water onto our pennies until it overflowed.  This was to show a couple things, first was Cohesion which is waters attraction to other water molecules.  The second was to show surface tension.  Because water is in love with itself, it wants desperately to be bound to 4 other water molecules.  Those water molecules at the surface of water have to hold on extra tight to the molecules beside and below it that it develops a sort of "film" at the surface.



Eventually the pressure would be too much and it would overflow, but the water molecules still are holding on to each other!!!!

Next we looked at surface tension with a different demo.......

We balanced a pin on the side of
the jar, let go and saw if we could get the pin to
float on the water



If you look very carefully, you can see how the water slightly "dips" in at where the pin is laying.  This is showing the how the  hydrogen bonds will "bend" a bit, but it takes a while to break

 Finally you started into Adhesion as we finished up the class period.

Wonders of water day 1

                              Thursday September 5th  

Based on this cartoon – What type of Bond is this “marriage” depicting since the guy states “I Do! Here’s my Valence Electron Baby” Ionic (In ionic bonds electrons are lost or gained, this causes charges and then the attraction of a negative ion to a positive ion.)

What if instead the “boy” atom said, “I do, Let’s share our valence electrons baby” Which type of bond would it be referring to? Covalent.  When electrons are SHARED, this is known as a covalent bond (which makes for a MUCH better relationship ;) 

We reviewed the last couple slides from yesterday and then started into the following notes/activities.

I had your cups of happy water ready on your desk for you..... as we stared our first slide



Then we built our first water molecule



The large red atom is the oxygen, the small white atoms
are hydrogen.



You then made smaller water molecules to see how water interacts
with other water molecules

I had you guess, based on your understanding of water structure, how two water molecules would bond with each other.

Most of you were able to infer that the hydrogen end of one water molecule would be attracted to the negative end
of another.

If time permitted, some of you then watched the "section trailer" for this....

Chemistry of Life day 2

We spent a long time today on daily questions in order to make sure you really understand the atomic basis of life.  Here was what i had you do as a warm up.

First I guided you to your notes about protons which mentioned that the atomic # corresponded with the # of protons, so quickly you  should have been able to fill in the number of protons the whole way down 

We then saw that the number of protons equals the number of electrons in a NEUTRAL (no charge) atom.  So you would also put that as the # of electrons on all of these EXCEPT the two ions.  I guided you  at that point to your notes on IONS and you should have found that an atom that has LOST an electron is POSITIVELY charged.  So that means our Sodium Ion (Na+) must have one LESS electron.  An atom that has GAINED an electron is Negatively Charged, so our Chloride Ion (Cl-) must have an extra electron. 

Next we discussed electron shells.  This is were electrons are found.  The first shell can hold 2 electrons, while each shell after can hold 8 each.  Valence electrons are those found in the outer most shell.  The easiest way to go about that is figure out how many electrons are in each shell, and the outer most shell is considered the "valence shell"  notice the smiles next to NA+ and Cl... this is because they are Happy to have 8 electrons in their valence shell.

Finally we moved to the last question.  The answer ended up being a math problem?!?!?!?!  What was I talking about here??? since oxygen has 6 valence electrons and wants 8, it will gladly bond with two hydrogen which each have 1 valence electron so it can be happy with 8 electrons!!!

WHEW!!!!!  That was an intense daily question for sure but laid the ground work for the rest of this VERY important chapter!!!
Today's notes

Now that we went through the daily question this slide should have made MUCH more sense.... and required me to play I need a dollar....... ;) 

So what happens when two ions come in contact.... this love story ends in the formation of salt!!!

I had you listen to the following podcast and we had a nice discussion about electrolytes