Lab Day!

So last class we did a lab! about physical and chemical change.

To help us really understand how the lab was going to work Ms. Chen had us make our own flow chart,
consisting of all the steps we had to do in order to make the lab work properly.

Remember always tie any long hair up, wear close toed shoes, and wear lab glasses at all times during a lab until the process is finished! we wouldn't want anything bad happening!

The equipment used were:

• 4 test tubes, labelled A,B,C and D
• a test tube rack
• 4 medicine droppers
• glass square

First off Ms.Chen gave us 4 different unknown solutions for each test tube. In the glass square we combined solutions, A and B, A and C, B and C, A and D, B and D and C and D.
As a result, when the solutions were combined they either changed in color or created tiny bubbles. 
From this we were to figure out weather the mixed solutions had a Physical Change or a Chemical Change.

To decide which one it is here's something to help you out:

1. A physical change is reversible, a chemical change is not. For example, the freezing of water would be a physical change because it can be reversed, whereas the burning of wood is a chemical change - you can't 'unburn' it 

2. A physical change is a change in which no new substance is formed; a chemical change results in the formation of one or more new substances.

Still dont get it? or are a visual learner, check out this vid!
http://www.youtube.com/watch?v=oQnPNBVmwuU&feature=related


Enjoy!

Quiz Day

Today (unfortunately) was quiz day!

but before we wrote our quizzes on Conversion we had a review on Matter!

What is Matter??

- it is anything with mass and volume

ex. pretty much everything you've ever known about (you, your clothes, your house, air, trees, animals etc.)

- Matter is made up of 2 parts: Pure substances  and  mixtures

This is were things get a little trickier!

Pure substances have only 1 set of properties however mixtures have more then 1

Within Pure substances there are elements and compounds

-we learned a lot about elements and compounds throughout grades 6 to 10

-just to sum it up, elements are in there simplest forms, and compounds are made of elements

Mixtures were a pretty new idea today, to be honest I cant really remember learning about them in the past.

homogeneous and heterogeneous are the 2 ways mixtures are physically combined.

that probably makes no sense right now (I thought so at first) but really it's not that hard

Homogeneous basically means you cant tell how many components there are, you can only see 1

- ex. milk or fog

Milk: only 1 visible component

Heterogeneous is the opposite, it is obvious that it has more then 1 component

-ex. water + oil mixed together

water + oil: more then 1 visible component

This seems like a lot of information, but I'm still not done!

Another thing we learned before our quiz was the difference between Physical and Chemical change, instead of telling you about it, here is a video that tells you about the 2 changes

http://www.youtube.com/watch?v=5yjEDihEuZI

I hope you enjoyed the video, with it's little song!!

After we learned all this new information we finally went on to our quiz! Which was what you see below this post!

Thursday, September 23rd, 2010

It's the long weekend this weekend! So today, the Happy Halogens worked on getting ready for our quiz on unit conversions for Monday. Here are some helpful resources so that you can feel confident and prepared to get that A+!

Using Julia's instructions, here are some extra practice questions to work on:

Questions

Answers

Also, if you want to try something just for fun, use this to convert anything you want to anything you want!

If you are still lost and confused and don't understand what is going on or how to do it (I know the feeling) this video will help clear up any problems:

The Greatest Unit Conversion Video Ever Made!

Enjoy!

Tuesday, September 21, 2010

Scientific Notation.
It may look hard, but once you get the hang of it...it isn't hard at all.
Basically, it's used to express very large or very small numbers, using powers of 10.
It's just a shorter method.
Instead of writing:

we write:

The first number, 7.53, is called the coefficient.

It must be in between 1 and 10. Greater or equal to 1, and less than 10. 

The second number is called the base. It must always be 10 in scientific notation. In the equation above, the number -8 is the exponent, or in other words, the power of 10. 

So how do we convert units into scientific notation?

For example: 

NOW WHAT?

It's actually pretty simple.

Make sure you cancel out units as you go!

So now you're left with 9.2 km3 and 103.

But wait! 103 is the denominator! You can't divide 9.2km3 into 103.

So to bring 103 up to the top, you have to make the exponent negative. 

Your final answer should be:

See? It wasn't too bad. As you practice, you'll just keep getting better and better.

"Take your time, don't rush, and you'll be fine." -Ms. Chen

Still not getting it? Try watching this useful video on scientific notation.

Scientific Notation Made Simple