Sept 30-- Lab with physical and chemical change

Objective:
to observe some different types of chemical changes.

Materials and Equipments:
 Reminder: always wear safety goggles!


1 test tube rack
4 small test tubes
1 glass square
4 medicine droppers
4 unknown chemicals

Procedure:
Refer to the Lab textbook on page 18

Result:

Conclusion:
Different chemical changes have different reactions, such as bubbles, changing colors, etc.

Sept 28--Matter

Question: What is a matter?

Answer: Anything around us that has mass and takes up space is called matter. :)

Pure Substances have only one set of properties and one kind of particle. 

Elements are pure substances that have the simplest form. They're made of atoms. Three types of elements are: metal, metalloid, and non metal.

Compounds are also pure substances. They are made of chemically combined elements. The smallest particle of a compound is a molecule. There are two types of compounds: ionic and covalent.

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Mixtures have more than one set of properties and substances. Unlike compounds, the substances are physically combined. Homogeneous and heterogeneous are two kinds of mixtures.

Solutions are homogeneous, which are uniform throughout and appear to have only one component.

The mixture of water and oil is one type of heterogeneous. It is not uniform, and appears to have more than one component.

Question: What is the difference between a physical change and a chemical change?

Physical Change	Chemical Change
- no new substance is formed	- new substances are formed
- chemical composition does not change
- reversible	- irreversible

Question: Are there any other properties of matter?

- Matter is neither created nor destroyed. It can only change from one form to another.

- There are three states: solid, liquid, and gas.

Solid	Liquid	Gas
- does not change shape easily	- takes the shape of the container	- takes the shape of the container
- won’t change too much in volume when heated	- changes slightly in volume when heated	- changes drastically in volume when heated

Sept,21--Scientific Notation

Scientific notation is used to write numbers that are too large or too small by using powers of 10.

1. To express numbers in scientific notation:

Ex. 25,100,000,000 = 2.51×1010

2. To convert numbers in scientific notation:

Ex. 3.25×108 = 325,000,000

Youtube Online Tutorial On Scientific Notation :)
This video actually helps you to understand more about scientific notation!

Using a Calculator

Find a button that looks like either of the two pictures shown. They both represent the powers of 10. By using this button, you can calculate numbers shown in scientific notation.

Converting the square or cube of different units:

Ex. 1 m = 100 cm

   1 m2 = 10,000 cm2

   1 m3 = 106 cm3

(In order to convert 1 m2 into cm2, you should first convert 1m into cm, and then square the number.)

chemistry 11