Monday, May 31, 2010
For you people that had the shame of missing our class, or just aren't part of it (which is also a shame), here is a definition of both:
- Exothermic Reaction: A change in which energy (or NRG) is released.
- Endothermic Reaction: A change in which energy is taken in.
So, the purpose question was "How do measured temperatures show the difference between an exothermic and endothermic reaction?"
In the actual lab, we mixed Yeast with Hydrogen Peroxide, and Baking Soda with Vinegar.
Yeast and Baking Soda being the Solutes, and Hydrogen Peroxide and Vinegar being the Solvents.
After consulting it with ms.D, we decided that the independent variable of the lab was temperature, and that the dependent variable of the lab were the endothermic and exothermic reactions.
The result of the first experiment was that Yeast and Hydrogen Peroxide became instantly very bubbly and hot, and stunk like rotten bread.
The second experiment was a bit slower, as the chemical reaction took longer to occur. The result was lots of bubbles and the container becoming cold.
All of the experiments went without any injury and everyone left with good data.
The whole lab is in our Chemistry Packet, so check it out!
If you still don't understand the difference between endothermic and exothermic reactions, here is a link showing some simple examples of them.
Thank you for reading my scribe post. I hope you enjoyed it and that it was helpful.
The next scribe is... well, I can't find the list of available scribes, so I'll have to ask ms.D.
Sunday, May 30, 2010
Friday, May 28, 2010
Other good thing about Blogger is that it is very easy to use. That's probably the fact makes me like it. You just enter the address in the URL box and that's it. I had fun working with Blogger and I think that my teacher, Ms. D should do the same Blogger project with next grades. Severyn :)
Thursday, May 27, 2010
Homogeneous vs. Heterogeneous
Molecular Proximity – distance of particles in a state of matter.
To see a Table about the States of Matter, please click on the link below:
States of Matter Table
Due Friday, May 28th:
1. The 7th Blog Comment. Remember, you must have three 8th grade comments, three 7th grade comments and two 6th grade comments.
2. Color in the TWO Periodic Tables in your packet - be sure to read the directions for what you need to do for each.
Follow the link below:
Moodle for 8th Grade
The next scriber is Daniel!
Tuesday, May 25, 2010
In class Friday we went over the liquids and solids observed in a lab on Thursday. As a class we decided which substance was compound which was an element and which substance was a mixture. After everyone went up and wrote substance under where they thought it belonged we all went through to check each-others answers. This is what we ended up with:
In the table below the numbers next to the letters underneath "symbols/formlas" are meant to be down lower and smaller-like in this image-
-over 3 parts in your book you read as homework
-your chart in the packet
-and the 2 sets of notes
- pure substance (simplest)
- can't be divided
- no "+"'s in formula
- and has only one chemical symbol
- pure substance
- 2 or more elements combined chemically
- has a ratio (always the same)
- ONE chemical formula
- 2 or more elements involved
- NOT CHEMICALLY combined
- 2 or more chemical formulas
- formulas have "+"'s
TYPES OF MIXTURES:
Homogeneous- uniform mixture, same throughout
Ex.cedvita, mineral water, salt water
Heterogeneous-not uniformed mixture, not same throughout
(Looks like a salad. You can tell where the tomato is, where the lettuce is, where the cucumber is; it all stands out)
Solution is a homogeneous mixture.
-Solute(what you have less of): part that dissolves
-Solvent(what you have more of, and usually a liquid): dissolving part
In salt water:
In mineral water-
Stated by Ms. D, "96% of the time H2O is the solvent"
ONE LETTER ELEMENTS:
TWO LETTER ELEMENTS:
THREE LETTER ELEMENTS:
And these are all, man-made solids, and last less than a second usually.
¬We also figured out how to read the substances formulas' using math.
In the formula above there are 4 hydrogens, because you multiply H x 3 and you get 3 hydrogens. Then add the H at the beginning. and you get a total of 4.
There are also 2 carbons and 2 oxygens used to create the substance.
In case you want to look up more formulas, this is a cool site I used:
Next scriber is Severyn.
Thursday, May 20, 2010
-ruler, graduated cylinder
Density: - the measurement of how much mass of a substance is contained in a given volume
Finally we got to our rotation lab on matter. In this lab we had to smell and examine 12 different substances and write down their symbol/formula, their physical properties, decide if the substance was a solid, liquid or gas and decide if it was an element, compound or mixture.
Here are some substances that were examined: .
- Copper- Cu, solid, element
- Hydrogen peroxide- H2O2 , liquid, compound
- Rubbing Alcohol-C3H8O, Liquid, compound
Tuesday, May 18, 2010
On May 14, 2010 we had a short Friday class, first everyone got their constellations project back graded. We watched the Myth Busters season 4 – this time the myth they tested was Mentos & Diet Coke.
Here is a link to the video that inspired the myth:
This video has gotten so many views on YouTube and all over the internet so the Myth Busters decided to test it.
This video is explaining about what they did in the experiment and what is happening inside the diet coke bottle:
Homework – answer the 9 questions about the Myth Busters experiment and read pages 6-15 in the textbook. Do Tuesday.
the next scribe is Holly
the next scribe is Holly
Friday, May 14, 2010
- Some say the universe will have a continual expansion
- Some say it will have a "big crunch" and it will all crunch together
- Others say that eventually everything is going to stop
Next scribe is Abigail
Tuesday, May 11, 2010
Last Friday, we spent class reviewing eachother's constellation fact sheets. Each student recieved 3 people for whom he or she was to read their sheets and grade them. Because that class was short and unchanging, I am also blogging for today's science class on May 11.
Today at the beginning of class we had a quick discussion about Branimir; the astrophycsicist that came to our class and talked to us last week. We wrote him some of our comments and criticisms on his lecture, which included the following:
Lack of media
Shorten his bullets on his powerpoint
Speak louder and clearer
Interact with the students more
Simplify some vocab
Showed enthusiasm and true knowledge of the subject
Interesting at most parts
Branimir has never taught to students our age; and I think he deserves an extra arm of applause for having the courage to do so now. In about three days, he becomes a doctor of astrophysics.
From the discussion, Ms.D continued to show us the Star Notes Powerpoint we had started to watch in one of our previous classes. Our final exam will include most of this information, which is why I will include a summary of the most important facts below.
-Blue stars are the partiers. They are hot, big, young and die fast.
-White stars are middle everything. Middle aged, middle sized and middle brightness.
-Red stars are old, colder and dying.
A globular cluster is a glob of stars
Galaxies are large systems of stars in dust (interstellar matter)
There are several million galaxies with several trillion stars in each one.
There are three main types of galaxy:
Our galaxy is a spiral galaxy
Have lots of interstellar matter
Has arms and a a black hole in the middle
-Very little interstellar matter
-No shape, distorted due to gravity from neighbouring galaxies
We know other galaxies exist because of the use of math, and pictures taken using radio waves
Additionally, we learned what a Hertzbrung Russel graph is. It is a graph that explains how stars age.
Next, we were taught how a star dies. There are basically three different ways of stellar death, and how they go is based on their mass.
-If the star is the mass of our sun:
Red Dwarf: Running out of fuel
Red Giant: Out of fuel
White dwarf-Hot, small star, dead when it runs out of energy
No worries, our sun won't die for another 4 million years, and we'll most likely die out by then anyways.
-If the star is 4x the mass of our Sun
Same steps as Sun
Past White Dwarf
Electrons+protons combine = neutrons= neutron star!
The neutron star then becomes stronger than nucleur forces inside of an atom
-If the star is 10x the mass of our sun
-Same steps as previous deaths
-Past neutron star
-Collapses past nucleur forces
-Forms a gravity well-cosmic vacuum cleaner
-Which then turns into a black hole
In the middle of our discussion, we also talked about atoms and molecules , and learned that zombies are actually just reanimated atoms.
At the end of class we began a discussion on the Big Bang, but ran out of time. For the next class the volleyball girls will not be here to take notes so I hope the next blogger does a supreme job of summing up the class.
We have no homework for Thursday.
Also the following link is something spiffy I found that stimulates all of the astronomical events we discussed in class.
Additionally, something I personally found intriguing was that when we look into space, we look into the past since things are so many light years away. For example, if there is a galaxy one billion light years away, we won't know its dead until a billion years from now.
The next blogger is Cornelia.
I like astronomy because of many reasons. The one reason is because it's very interesting and unexplored. The space is very, very big and unknown. You never know what you can find in the universe. Maybe there are some other creatures in other planets. We can't never know how are they living, maybe they are more developed then humans and technologicaly. The universe is so big that we can't know if there are some planets that maybe we can live on it. Because of all these reasons, I think astronomy is a great scientific discipline. You never know what can you discover about universe.