LAB 2C : physical and chemical change

So, two days ago..we had a lab and we got to observe different changes being formed by adding different solutions together! It was kind of fun :) ( except the cleaning part of course, it got really messy haha)

For those people who are forgetful like me *ahem* there's an upcoming test on chapter 1 and 3 on October 21st.

Well that's about it!
More post coming soon!


Here's a video on chemical changes. Watch it if you want, if not then you might as well leave. there's nothing more to see here.
http://videos.howstuffworks.com/hsw/8685-states-of-matter-chemical-changes-video.htm

Nevertheless, thanks for visiting!

What is Matter?

After studying long and hard for our chemistry test today, it's finally over! Now we begin to learn about matter.

What exactly is matter? Well in Ms.Chen's words it's...

"Anything that has mass and takes up space (volume)."

Basic Info on Matter:
-It is never created nor destroyed (only changed from one form to another)
-There are 3 states of matter:
1. Solid: rigid, does not change shape easily and experiences small change in volume when heated.
2. Liquid: takes the shape of the container and experiences slight changes in volume when heated.
3. Gas: Takes shape of container and experiences drastic changes in volume when heated.

Now that you have an idea of what matter is, it's time to go over different types of matter and their properties.

Red = Pure Substances --------- Blue = Mixtures

Pure Substances:

- One set of properties

- One kind of Particle

Element:

- Simplest form (can not be decomposed)

- Made of atoms

- Metals, Non-Metals, and Metalloids are all Elements.

Compound:

- Made of elements

- Chemically combined

- Smallest particle is a molecule

- Ionic and Covalent are compounds

Mixtures:

- More than one set of property and substance

- Physically combined

Homogeneous:

- Uniform throughout

- Appears to have only one component. (Ex. Solutions)

Heterogeneous:

- Not uniform

- Appears to have more than one component (Ex. Water + Oil)

- Suspensions and Mechanical Mixtures are Heterogeneous.

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Physical and Chemical Changes

You probably already know what the difference between physical and chemical change is, but just incase you don't remember, here they are.

Physical Change:

- No new substance is formed

- Chemical composition is not changed

- Reversible (Ex. You can freeze water and melt it back.)

Chemical Change:

- New substances are produced

- Irreversible (Ex. If you burn something, you can't unburn it.)

That's all the chemistry for today! Yay :) Thanks for reading, have a good day.

Review : Unit of Conversion

      YES! Its the long weekend! Just what we need. A time to relax and of course.. study for our quiz next class. (:
So today, we did a review of unit conversions with quantities.

      Here's a useful table you will need to know for the quiz, including the conversion factors ( not shown here ; refer to Ms. Chen's sheet)

Here are some examples: 

.

Need more practice or a little more challenge ?

visit: 

                                >>http://serc.carleton.edu/mathyouneed/UnitExample.html<<
                                >>http://chemistry.about.com/library/weekly/blconverquiz.htm<<

Scientific Notation and Even More Unitary Rates

Scientific Notation (exponential notation)

• a way of writing numbers that accommodates values too large or small to be conveniently written in standard decimal notation
• is written like this  a×10^^b   and 1 ≤ |a| < 10
• eg. a)   323 will become 3.23 ×10^² 

                   b)  0.000004128 will become 4.128  ×10^^-6

• in calculator, the letter ''E'' or ''e'' represents times ten raised to the power of, thus replacing the × 10, followed by the value of the exponent  
•  if you want to enter 6.02 ×10^²³ then you press  6.02 E 23

• In Addidition or Subtraction, make sure all numbers are converted to the same power of 10, and the digit terms are added or subtracted. 

• In Multiplication or Division, The digit terms are multiplied (or divided) in the normal way and the exponents are added (or subtracted) 
• further information on basic operation can be found at  http://www.youtube.com/watch?v=iHrAMLY5-A0&feature=related

Even More Unitary Rates

• convert the unit which is squared or cubed
• if 1km = 10³m, what is 1km², 1km³ equal to ? 
• the answer will be 10⁶m² and 10⁹m³ because 10²⁽³⁾ and 10³⁽³⁾
• if the unit is squared, then the power will be doubled
• if the unit is cubed, then the power will be tripled....and so on
• Ex.   8.93m^² to cm^²

                   1m^² = 1000000cm^²  , 1m^²× 8.93 = 8930000cm²= 8.93×10⁶cm²

            ^{**WATCH VIDEO**  [ how to convert units]
                **WATCH VIDEO**   [discovering math - scientific notation]}