Unit 2: Matter

Put everything for this unit behind the second tab!

Topic 4.D – Classifying Matter

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Classifications of Matter

Homogeneous Mixture

Same throughout

Heterogeneous Mixture

Varies in content

Mixtures

Contain more than

one kind of matter

Element

All atoms are the same

Compound

Consists of two or more

types of atoms

Substances

Cannot be separated into different

kinds of matter by physical means

Matter

Anything that has mass and takes up space

Mixtures

• Contain more than one kind of matter

• Can be separated physically

a. Sorting

b. Filtering

c. Heating and cooling

Types of Mixtures

a. Homogeneous mixtures – are the same throughout; every sample has the same ratio of ingredients

Ex: milk

b. Heterogeneous Mixtures – vary throughout; each sample may have a different ratio from the next

Ex: chicken soup

Mixture Examples

• Petroleum (Crude Oil) – 1,000,000 molecular compounds

• Soda – Carbonated water, corn syrup, caramel color, phosphoric acid, natural flavors and caffeine

• Paint – Pigment, Latex, thinning agents

Pure Substances

Cannot be separated by physical means

May contain more than one kind of matter held together by chemical bond

examples: Lithium, NaCl

Types of Substances

a. Elements – Contain only one kind of matter; (one kind of atom)

b. Compounds – contain two or more elements; can be separated chemically

Topic 4.C - Phases of Matter

Phases of Matter

gas liquid solid • most movement (high kinetic energy) •shape and size is dependent on the container a liquid is in •Molecules can be compressed closer together • least dense phase

• molecules are touching, but “slide” around each other (FLUID motion) •shape and size is dependent on the container a liquid is in

•molecules are touching and vibrate in place •solids have a definite shape and size

• MOST dense phase

“fluids”

Topic 4.B - Properties of Matter

Types of Physical Properties

• Something you can observe or measure without changing the matter into something else.

• For example, you can measure how much something weighs or what it smells like without changing it into something else.

• You cannot tell if something will burn without changing it into something else.

Types of Chemical Properties

• The ability of something to react with something else or to change into something else.

• You cannot observe chemical properties without changing the object into something else.

• For example, if you observe that a nail will rust, it has already changed partially from iron (the nail) into iron oxide (the rust)

Intensive vs. Extensive

• Intensive properties: characteristics that do not depend on the amount of matter present.

– example: density

• Extensive properties: characteristics that depend on how MUCH matter is present

– example: mass

Intensive Properties

• Properties that do not change depending on how much stuff you have.

• These are observable whether you have a lot or a little of it.

• For example, a diamond will be sparkly and lustrous no matter if it is tiny or giant.

Extensive Properties

• Properties that change depending on how much stuff you have.

• These will change if you have a small amount or if you have a large amount.

• For example, a small sample of sand will have less mass than a large sample of sand.

Density

how tightly packed the particles are in a substance (“compactness”)

The relationship of

mass to volume

Intensive or extensive?

• Less dense = float

• More dense = sink

• example: substances that are less dense than water will float on water.

Viscosity

resistance to flow

Viscous fluids are thick and hard to pour

Large molecules flow more slowly (MORE VISCOUS)

Small, smooth molecules flow

more quickly (LESS VISCOUS)

Intensive or extensive?

Malleability A solid’s ability to be

pounded into thin sheets

Ductility

the ability to be made into wire

Intensive or extensive?

Intensive or extensive?

Conductivity

• The ability of a material to conduct electricity, heat, or sound

Intensive or extensive?

Melting Point

• temperature at which a solid melts to beome a liquid

• temperature at which a liquid boils to become a gas

Boiling Point

Intensive or extensive?

Intensive or extensive?

Luster

• how much the surface of a material reflects light (“shine”)

• example: chrome

Intensive or extensive?

Solubility • the ability of one substance to

be dissolved in another substance

• solubility can depend on temperature, pressure, and how much of each substance is interacting

Intensive or extensive?

Reactivity

Copper Reacts with Nitric Acid Magnesium Reacts with

Hydrochloric Acid

Describes how readily a substance will undergo a chemical reaction with another substance

Toxicity

• The degree to which a substance can damage an organism

• While even a small amount of toxins can hurt you, how toxic something is depends on how MUCH there is

Corrosiveness

• A measure of how much a substance can destroy or

irreversibly

damage another

surface or

substance with

which it comes into

contact.

Often strong acids and bases.

Flammability

• How easily something will burn or ignite

7 Sep. 2012 1. Warm Up: by the

door (Classifying and Properties)

2. POP QUIZ!

3. Video: ITP: How to light a Bunsen Burner

4. ½ Class Practice: Bunsen Burner lighting

5. 1/2 Class: Make up work:

- Classification of Matter, #1-13

- Density Practice I, #3-5

- MSDS Exploration

- Density Inquiry Lab (Prob 1 or 3)

6. ITP: Safety Review Video

Topic 4.A - Changes in Matter

Unit 1 – Organizing Matter - 2011

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Physical vs. Chemical

• Physical change - same substance before and after

• Chemical Change – make a new substance

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Physical Changes

• Affect only physical properties:

– size

– shape

– state

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Examples of Physical Changes

• Shattering glass

• Crushing ice

• Letting ice melt

• Compressing a gas

• dissolving

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Phases or states are: solid, liquid, gas

(and plasma)

changes from one state of matter to

another

based on the addition of or loss of

energy (heat or thermal energy)

Phase Changes (a.k.a. “changes of state)

Phase Changes (a.k.a. “changes of state)

• Melting: solid to liquid

• Boiling or Evaporation: liquid to gas

• Condensation: gas to liquid

• Freezing: liquid to solid

• Sublimation = solid straight to gas!

Chemical Changes

• The result of chemical reactions

• Bonds must be broken and/or created to form a new substance(s)

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How do you know if a chemical change has occurred?

• Product is obviously different than starting materials

• Energy has been released or absorbed (careful – did you add the energy?)

• Obvious changes in: – Color

– Texture

– Opaqueness

– Gas bubbles form (not boiling!)

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