September 29 2010 - Lab 2C Chemical and Physical Change

Today, we did a lab for chemiacal and physical change.

Purpose of this lab is to find out characteristic of chemical and physical changes and to know difference between chemical change and physical change.

Material :

Equipment

4 small test tubes glass square
(10mm x 75mm) lab apron
test-tube rack safety goggles
4 medicine droppers

Chemical Reagents

set of 4 unknown solutions


Procedure :





Experimental Results :





As a result, combination of solution D and A, D and B, and D and C are chemically changed.
These combinations have characteristics of chemical changes that changed color. Also combination of solution B and C is a chemical change due to characteristic of chemical change which is forming new substances.

September 27 2010 - Matter and Physical/Chemical Change

Today, we went over a common topic in science: matter. Matter is any object that takes up space and has a mass.

Matter is split into two categories: pure substances and mixtures.


Pure substances have only one set of properties, and only one kind of particle. Pure substances are split into elements, which are the simplest form and are made out of atoms (metal, non-metal and metalloid), and compounds, which are chemically compounded, made out of elements, and have small particles within them called molecules, which can be ionic or covalent.

Mixtures are the complete opposite, having more than one set of properties. Mixtures are grouped into homogeneous, being uniform throughout and only having one component, and heterogeneous, being non-uniform and having more than one component.

We also reviewed physical and chemical change, mainly looking at their differences.



Physical change is reversible, while chemical change isn't. It doesn't add any new substances into the product, unlike chemical change. Physical change also leaves the chemical composition the same as it was before the change.

September 23 2010 - Review

Today, we review unit conversion and unitary rates. Which we have done many reviews and worksheets for.

Not only did we review but we also had a Practice Quiz on the material we will be quized or tested on next week. Which includes :

-Unit Conversions- ( given quantities and derived unites)

eg. Convert 3 s into milliseconds

eg. Convert 28.4 g/mL into kilograms per litre

-Unitary Rates-

eg. Convert mm into km

-Scientific Notation

eg. Put 1232133 km into scientific notation

(1.232133 x 10⁷⁾

Also i really enjoyed the shorter 50 minute class ;D

September 21 2010 - Unitary Rates

We re-reviewed Unitary Rates, which we've gone over many times.

Quantities are combinations of numbers and units. You have to have a combination of numbers and units because they don't make sense without each other. It'd be like saying, "This costs 457.09" or "I ate 9" (assuming, of course, that you aren't 7. HARHARHHAR MATH JOKE)

The Systeme Internationale, or the SI, is a French system using powers of 10. We call this system the Scientific Notation system (covered in the last post).

A handy unit conversion chart :
http://www.austinpowder.com/BlastersGuide/blasterstools/_graphics/table-unit-conversion.gif

- Esther

September 21 2010 - Scientific Notation

First blog post! :) (other than the test post. That doesn't count)

Today, in class, we learned about Scientific Notation. We should have already learned this in grade 9 already, so this was more of a review.

Scientific notation is used to express very large or very small numbers using powers of 10.

For example, 25,100,000,000 would be expressed as 2.51x10^10, because for scientific notation, the number in the front has to be a number bigger than 1 and less than 10 (eg. 2.5, 6.7, 2.78). First, you move the decimal point (which is after the last digit [eg. 3487000 would be 3487000.0]) to the left until the number is between 0 and 10. Then, count the number of decimal places you moved over, and beside the new number, add a 10^# (10 to the power of #).

0.000000030 would be expressed as 3.02x10^-8. For negative equations, you move the decimal to the right instead of the left.




On the other hand, 3.25x10^8 would be expressed as 325,000,000, because you would move the decimal place over 8 spaces.



How to use Scientific Notation on a calculator:
1. Punch in the decimal number from 1-10
2. Press the 'EE' button
3. Punch in the power (10^17, press in 17, NOT 10^17)
4. Press ENTER :)

Alternate way (for dummies)
1. Punch in the decimal number from 1-10
2. Punch in 10
3. Punch in the (^) symbol
4. Punch in the power
5. Press enter :D

- Esther

September 20 2010

Test post? :D
- Esther