ch 11 8th grade lessons 1&2

CHAPTER 11-LESSONS 1 & 2Miss Reaves

8th Grade Science

WHAT YOU WILL DO TODAY:

1. First time-Just listen and watch this presentation. Don’t take notes!!

2. Watch the presentation a second time. THIS time, fill in the blanks in your notes.

3. DO NOT freak out if you miss something!!!! This is posted on the 8th grade page of KMSstudent.com.

4. Complete Vocabulary Squares in class and for homework.

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

SUBSTANCES

MIXED SUBSTANCESOR

MIXTURES

PURESUBSTANCES

HETEROGENEOUS HOMOGENEOUS

LIQUID SOLUTIONS

GAS SOLUTIONS

SOLID SOLUTIONS

COMPOUNDS ELEMENTS

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

SUBSTANCES

PURE SUBSTANCES: they have well defined specific properties: density, fusion, boiling temperatures…

MIXTURES: they are made up of two or more different substances. They do NOT have well defined

Specific properties.

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

MIXTURES

HETEROGENEOUS: we can clearly distinguish the different components. Some examples include

salads, soups, and cookies. 

HOMOGENEOUS: we cannot see the different substances that make up a mixture.  Some of

examples include alcohol and water.

Concrete, conglomerate rock, as well as oil and vinegar are all heterogeneous mixtures. The particles are large enough to be seen and can be separated from the mixture.

Homogeneous mixtures are very well mixed. A salt solution is a homogeneous mixture. 

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

HOMOGENEOUSMIXTURES

LIQUID SOLUTIONS: we usually speak of solutions for liquid mixtures.

GAS SOLUTIONS: like the air.

SOLID SOLUTIONS: like steel which is a mixture of iron and carbon.

Have you ever put sugar in a glass of milk? After you stir, you can no longer see the sugar. The sugar is still there, as you can taste it. A mixture of sugar and milk is called as solution. By evaporation we can separate the different kinds of matter in solution.

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

PURE SUBSTANCES

COMPOUNDS: They can be broken down into simpler substances using chemical methods.

ELEMENTS: They can’t be broken down.

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

SEPARATION TECHNIQUES

DECANTATION

FILTRATION

MAGNETISMSIEVING

DISTILLATION

CRYSTALIZATION

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

Filtration is commonly the mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by

interposing a medium through which only the fluid can pass. 

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

Magnetism is a process in which magnetically susceptible material is extracted from a mixture using a magnetic force.

htt

p:/

/iesp

ebili

ngue.w

ikis

pace

s.co

m

Distillation is a method of separating mixtures. It is a process in which a liquid or vapour mixture of two or more substances is separated into its component fractions, by the application and

removal of heat.

SOLUTIONS, SUSPENSIONS, AND COLLOIDS

GOAL:

To classify mixtures as solutions, suspensions, or colloids.

IT’S ALL ABOUT THE PARTICLES!

The size of the particles has a great effect on the properties of a mixture.

You must observe a mixture’s properties before deciding whether it is heterogeneous or homogeneous.

Mixtures get classified as solutions, suspensions, or colloids based on particle size.

SOLUTIONS

Q: When iced-tea mix is dissolved in water, it forms what kind of mixture?

A: HOMOGENEOUS MIXTURE

When substances dissolve and form a homogeneous mixture, the mixture is called a solution. Whatever substance there is more of is called the solvent. The other is called the solute (ex. Iced tea-the solvent is the water, the solute is the tea mix).

SOLVENT VS. SOLUTE

PROPERTIES OF A SOLUTION They do not separate into layers over time. If they are poured through a filter, none of

the substances will get trapped. Light passes through them.

All of the particles in a solution are too small to become separated, filter out, or scatter light.

SUSPENSIONS

Flour in water, like other liquids that need to be “shaken well before using”, are called suspensions.

Muddy water taken from a swamp is another example.

PROPERTIES OF A SUSPENSION Heterogeneous mixture

Separates into layers over time.

Filters can separate particles that make up a suspension.

Particles are larger than those in a solution.

Scatter light.

Suspended particles settle out of a suspension.

COLLOIDS

Colloids contain some particles that are intermediate (in the middle) between those in a solution and those in a suspension. Examples include peanut butter, pudding, Jello, whipped cream, and even fog!

PROPERTIES OF COLLOIDS Do not separate into layers. Particles will not become trapped by a filter. Scatter light.

Colloids and suspensions appear cloudy; unlike solutions which are much clearer.

Colloids and solutions will not separate into layers; suspensions will.

VOCABULARY WORDS (FOR VOCAB SQUARES)

1. Solution2. Suspension3. Colloid4. Solute5. Solvent6. Filtration

Define Sketch(COLOR!)

Example Non-example/Opposite

THE END

For the rest of class and for homework, complete the vocabulary squares.

Use your text book if you need to. Ch. 11 pg. 388

Don’t forget to bring your new IAN tomorrow!!!

Thank you!!!!!!!