Thursday, September 30, 2010

[LAB DAY!] Chemical and Physical Changes. Y'all.

The theme of our post today, is the Southern Accent. 

Hai y'all. As y'all know Chemistry ain't no joke ny' more. Now we ain't meanin' to be aggravatin' y'all, but we're gunna needa pull our legwarmers up and get summa that edgy-cation our folks are always talkin' bout'.

Now that you have all had your giggles and snorts. Let us dive right in. 

Recall that we had 3 objectives in mind before we began the lab.

1) to observe changes while working in the lab
2) to understand why each reaction is chemical or physical
3) to record recognizable characteristics of chemical changes

Basically, this is what Ms. Chen WANTS us to gain from this lab. Ahem.
Which... we did. Right? (SAY YES.)

Well, we aren't going to write out all the procedures because normal people wouldn't have a long enough attention span to read it all. SOO we're going to sum it up for your benefit. You're welcome. :)
(Thank the Lord that you all are normal. Well... most of you all anyway.)

Because it's "important", we are going to list all the materials used in the lab... good for future reference!
- 4 small test tubes
- test-tube rack (We seriously wonder whether or not these were made in woodworking class by some unfortunate soul who had to make this boring thing as their final project!)
- 4 medicine droppers
- glass square
- lab arpon
- safety goggles
- 4 unknown solutions

Anywhooo, so we were given 4 mysterious highly toxic and illegal solutions.
(Because our well being is not a priority. Duh.)

Four solutions we labeled A, B, C, and D.
We mixed B+A, C+A, C+B, D+A, pigs+mushrooms, rats+lions, bubble tea+pottery ....... and we got a RAINBOW : D

Okay well maybe we didn't quite mix the last few but you get the point. (But wouldn't it be cool if we did?)
So, what we had to do was place all these different solutions together in a glass dish and see what kind of magical scientific reaction occured when they mixed.

If the mixture was bubbling or fizzy or changing colour, we could tell definately that it was a chemical change. So basically, anything strange that occured (like the fact that we have HST) you know its a chemical change.
If the mixture stayed the same and nothing happened to it (like you refusing to move from the couch when you're chilling and pigging out) then you know its a physical change.

Monday, September 27, 2010

We're Missing Monday Night Football =.=

Instead of dreading over the fact that you are missing Monday Night Football because of chem, let's imagine that you're actually at the stadium watching Jay Cutler and Rodgers duke it out. Now, although you know Cutler will probably mess it up, just imagine his stance before he throws the ball. His arm is up high behind his head, sweat trickling down his forehead, and BAM, he throws it in the air to have someone other than a receiver receive the ball.
Recall the three types of matter you learnt about in previous grades. Try and point out all three, using the given scenario.

Answer: The ball is a solid, the sweat trickling down his forehead is a liquid, and the air is obviously a gas.
Now wouldn't it be cool to actually go inside the ball? I think so. When inside, you see that the particles are so tightly packed that you can hardly move and you start to suffocate! You quickly move on to the liquid, his sweat. The particles are less tightly packed here, meaning that a liquid would take the shape of the container its in. Lastly, you pay attention to the air around you. You reach out and swipe at it. WOW. Magically, your hand goes through the air!  The particles in the air are spread really far apart and are always moving. Gases also take the shape of the conatiner they're in.

NOW. I bet all of you ask this question daily because it is just so darn interesting.
Well my friends, matter is anything that has mass and takes up space. It is neither created nor destroyed, only changed from one form to another.

Matter is composed of Pure substances and Mixtures. Pure substances have one set of properties and one kind of particle. Mixtures are quite the opposite. They have more than one set of properties and substances and they are physically combined.
To make it even more difficult for students with low brain capacities and low attention spans, Pure Substances are composed of Elements and Compounds! Elements are the simplest form, meaning they cannot be decomposed and they are made of metal, non metal, and metalloid atoms. Compounds on the other hand are made of elements, they are chemically combined, and the smallest particles is an ionic or covalent molecule.

Well even though we're pretty sure we lost you, we're going to continue anyways...because we're cool kids.
WELL THEN. Mixtures are composed of two groups as well. Homogeneous and Heterogeneous. Homogeneous are uniform throughout and appear to have only one component. Heterogeneuous are not uniform and appear to have more than one component.


The last topic we are going to cover is Physical and Chemical Change.
Physical Change is when no new substance is formed and chamical composition does not change. Physical Change is reversible.
For example: Melting ice. You can un-melt ice meaning it is
Chemical Change is when no new substance is produced. Chemical Change is irreversible.
For Example: Cooking a steak. You cannot uncook a steak. You can try to, by putting it in the freezer or chopping off all the seemingly cooked bits and feeding them to your dog but NO. I am sorry to say you cannot un cook something that has been cooked. Therefore it is irreversible.

THANK YOU. We love you. We really do.

The Day After Visiting Ancient Greece.

Well basically, we did not learn anything new this class so...refer back to our previous blog :D

We are in the midst of studying. More posts soon. You should study too, my disciples.


We feel bad about leaving this post so empty, so please enjoy this picture of a cow:

Tuesday, September 21, 2010

Unit Conversions In Ancient Greece

     Imagine you are in Ancient Greece! You're there at the time that Socrates began conducting his ancient experiments. You, being a fellow farmer in Greece, wanted to calculate the area of your farmland, but OH NO- you only knew how to count metres using your armspan. :( You suddenly have an intense epiphany! You remember that a wise man once told you that area is just length X width! Therefore, the area of your field can be calculated using armspan squared

Here are your measurements:

Length = 20 arm spans
Width = 10 arm spans

If in one arm span, there are 10 thumbs, and the area of the field is 200 arm span squared, what would the area be in thumb squared?

Your Farm

If you need some help, we've broken down the steps:

Step 1: Write the number and unit that you wish to convert. In your case, you are converting 200 arm spans squared, which is also:

200 arm spans²          10² thumbs²          20000 thumbs² OR 2.0 x 10thumbs²
_______________  x   ____________  =                             
          1                      1² arm span²        

NOTE: Remember to not only square the unit, square the number too!
          ex/ 10 thumbs = 10 thumbs² WRONG
                10 thumbs = 10² thumbs² RIGHT (10 thumbs x 10 thumbs)