1. Bell Ringer Aug. 23
If gases are compressible, why does a balloon filled with helium pop when you squeeze it in you hands?

2. Classifying Matter by Composition
Another way to classify matter is to examine its composition.
composition includes:
types of particles
arrangement of the particles
attractions and attachments between the particles 2

3. 3

4. Group Notes
You have 20 minutes… All group members must have the notes in their notebooks.
Use the Wi-Fi….

5. Pure Substance Examples:
Matter whose composition does not change from one sample to another is called a pure substance.
made of a single type of atom or molecule
Because the composition of a pure substance is always the same, all samples have the same characteristics.
Examples:
Elements
Compounds

6. Mixture blend of 2 or more types of matter
each component keeps its own identity and properties
the components are only physically mixed
can be separated using physical means
properties of the mixture are a combination of the component’s properties
Examples:
Heterogeneous Mixtures
Homogeneous Mixtures

7. Element
Pure substances that cannot be decomposed into simpler substances by chemical reactions are called elements.
These are found on the periodic table of elements
decomposed = broken down
basic building blocks of matter
composed of single type of atom
though those atoms may or may not be combined into molecules

8. Compound Substances that can be decomposed are called compounds.
chemical combinations of elements
composed of molecules that contain two or more different kinds of atoms
All molecules of a compound are identical, so all samples of a compound behave the same way.
Most natural pure substances are compounds.

9. Homogenous Mixture
homogeneous = mixture that has uniform composition throughout
Every piece of a sample has identical characteristics, though another sample with the same components may have different characteristics.
atoms or molecules mixed uniformly

10. Heterogeneous Mixture
heterogeneous = mixture that does not have uniform composition throughout
contains regions within the sample with different characteristics
atoms or molecules not mixed uniformly

11. Determine whether each of the following is element, compound, homogeneous mixture or heterogeneous mixture.
air
zinc
chlorine
granite
aluminum
sugar in water
blood
Sucrose (C12H22O11)
stainless steel
sodium chloride (NaCl)
brass
whole milk
apple
table salt (NaCl)
soft drinks
vinegar
concrete
sodium
baking soda (NaHCO3)
gravel

12. Closing Task Aug. 23
Write a 4 sentence summary about the differences between mixtures and pure substances.