a, b, & c If it has mass & volume , it’s matter

a, b, & c If it has mass & volume, it’s matter

a. anythingb. something

c. everythingd. nothing

How do we identify matter? “matter” = stuff

By what we can see, smell, taste, feel, hear, measure, … we call these things “properties”

Stuff can have 2 types of properties: Physical Chemical

Color:

Texture:Hardness:

Conductivity:Freezing/melting/boiling point:

Malleability:Ductility:

Solubility:Viscosity:

State:

Density:

Luster:

(measured without changing the stuff’s identity)

The organization of matter (e.g. solid, liquid, gas)The visual perception of reflected wavelengths of light

How something feels on the skin (soft, course, bumpy)How solid/hard something isHow well it allows heat or electricity to flow

Temperature that it freezes/melts/boilsAbility to be hammered into sheetsAbility to be pulled into wiresHow shiny it isHow well it flows (or how thick it is)Ability to be dissolved in waterThe mass of stuff per volume (#grams/1 mL)

• Reactivity• Toxicity• pH• Oxidation• Ignition point• Flammability

(changes the stuff’s identity when it’s measured)

If the change can be undone, it was a physical change.

For example: • water freezing into ice• throwing wood in a chipper• chewing up a carrotThe matter doesn’t change its chemical composition… it has all the same physical properties it did before the change.

Identifying a physical change…Ask yourself: “Self, can I undo that

change?”

▪ Or “Does this stuff have all the same properties as it did before?”

If the change can never be undone, it was a chemical change.

For example: • a nail corrodes/rusts• burning wood chips• I digest a carrotThe matter changes its chemical composition… it actually becomes new & different stuff.

Identifying chemical changes…When stuff changes it’s identity

(chemically changes), it is easy to tell. You may see… Bubbles A color change Light Heat Change in odor/taste

• The physical properties of sodium metal can be observed or measured. It is a soft, lustrous, silver-colored metal with a relatively low melting point and low density.

• Hardness, color, melting point and density are all physical properties.

• One of the chemical properties of alkali metals such as sodium and potassium is that they react with water. To determine this, we would have to combine an alkali metal with water and observe what happens.

• In other words, we have to define chemical properties of a substance by the chemical changes it undergoes.

• Physical properties may be intensive or extensive.

• Intensive properties (such as density, color, conductivity, ductility, boiling point … etc.) do not depend on the size of the sample of matter and can be used to identify substances.

• Extensive properties such as mass and volume and length totally depend on the quantity of the sample.

MatterMixtures:

physical combinition of 2

or more substancesHomoge

nous: SmoothSolutio

ns: totally clear/d

on’t scatter

light

Heterogenous: chunky

Substances: Pure stuff…

that’s allElemen

ts: Simplest form of matter.

Found on the

periodic table

Compounds:

2 or more elements chemicall

y combined

Classification of Stuff

Substances can be either an element or a compound

A substance cannot be further broken down or purified by physical means. A substance is matter of a particular kind. Each substance has its own characteristic properties that are different from the set of properties of any other substance.

• Fixed composition• Cannot be separated into simpler

substances by physical methods (physical changes)

• Can only be changed in identity and properties by chemical methods

• Properties do not vary

Compounds

• Can be decomposed into simpler substances by chemical changes, always in a definite ratio

Elements

• Cannot be decomposed into simpler substances by chemical changes

Mixtures are two or more substances that are NOT chemically combined.Mixtures do not:

      Have constant boiling points

      Have constant melting points

• Variable composition• Components retain their

characteristic properties• May be separated into pure

substances by physical methods• Mixtures of different compositions

may have widely different properties

Homogenous mixtures look the same throughout but can be separated by physical means (dissolution, centrifuge, gravimetric filtering, etc.). Examples: milk, yogurt

• Have the same composition throughout

• Components are indistinguishable

• May or may not scatter lightExamples: milk, yogurt, etc.

Solutions are homogenous mixtures that do not scatter light. These mixtures are created when something is completely dissolved in pure water. Therefore, they are easily separated by distillation or evaporation.

Examples: sugar water, salt water

Heterogeneous mixtures are composed of large pieces that are easily separated by physical means (ie. density, polarity, metallic properties).

• Do not have same composition throughout

• Components are distinguishableExamples: fruit salad, vegetable

soup, etc.

Colloids are solutions. They can be described as a substance trapped inside another substance. They can be identified by their characteristic scattering of light.

For example: air trapped inside the fat molecules in whipped cream.

MatterMixtures:

physical combinition of 2

or more substancesHomoge

nous: SmoothSolutio

ns: totally clear/d

on’t scatter

light

Heterogenous: chunky

Substances: Pure stuff…

that’s allElemen

ts: Simplest form of matter.

Found on the

periodic table

Compounds:

2 or more elements chemicall

y combined

Classification of Stuff *REVIEW*

Which of these is a homogenous solution???Which of these is a compound???

Name 2 Intensive properties:::

Name 2 Extensive properties:::

• Solids• Liquids• Gases• *Plasma

(And how the Kinetic Molecular Theory explains them all)

Kinetic Molecular Theory …Translation: The movement of the molecules determines the state

Vocabulary Mass- The amount of matter in a thing

Volume - the amount of space a thing takes up/occupies

Condensation - the process of changing state from a gas to a liquid.

Evaporation - the process of changing state from a liquid to a gas.

Melting - the process of changing state from a solid to a liquid.

Sublimation - the process of changing state from a solid to a gas without going through the liquid stage.

•Have a definite shape•Have a definite volume

• This means they are not compressible

Molecules are held close together and there is very little movement between them.

Kinetic Molecular Theory

• Have an indefinite shape• Have a definite volume

• So are liquids compressible?

Atoms and molecules have more space between them than a solid does.

Kinetic Molecular Theory

•Have an indefinite shape•Have an indefinite volume

• Compressible yet?

Molecules are moving in random patterns with varying amounts of distance between the particles.

Kinetic Molecular Theory

The state/phase of something can be changed by either adding/subtracting heat AND/OR pressure

How can we melt a solid to a liquid?

How can we boil a liquid to a gas?

How can we condense a gas to a liquid?

Add heat

Add heat… or lower the pressure

Remove heat… or raise the pressure

Solid Liquid Gas

Shape

Volume

Compressible?Particles

Definite

Definite

Indefinite

Definite

Indefinite

Indefinite

check yo’self

NO NO YES

Very Close Very farClose

DENSITY

Density = Mass of a substance in a sample divided by sample’s volume.

= mass/volume = grams/mL = grams/cm3

*It does not matter how much of the substance you have… the density will always be the same

Density

A piece of pure chalk has a mass of 17 grams and occupies 6.8 mL of volume. Find density of this piece of chalk…

Mass = 17 gVolume = 6.8 mLDensity = mass / volume = 17 g /

6.8 mLDensity = 2.5 g / 1 mL

Plasma is by far the most common form of matter. Plasma in the stars and in the tenuous space between them makes up over 99% of the visible universe and perhaps most of that which is not visible.

On earth we live upon an island of "ordinary" matter. The different states of matter generally found on earth are solid, liquid, and gas. We have learned to work, play, and rest using these familiar states of matter. Sir William Crookes, an English physicist, identified a fourth state of matter, now called plasma, in 1879.

(Above)

X-ray view of Sun from Yohkoh, ISAS and NASA

Star formation in the Eagle Nebula

Space Telescope Science Institute

, NASA

(below)

Plasma radiation within the Princeton Tokamak during operation.

Plasma consists of a collection of free-moving electrons and ions - atoms that have lost electrons. Energy is needed to strip electrons from atoms to make plasma. The energy can be of various origins: thermal, electrical, or light (ultraviolet light or intense visible light from a laser). With insufficient sustaining power, plasmas recombine into neutral gas.

Plasma can be accelerated and steered by electric and magnetic fields which allows it to be controlled and applied. Plasma research is yielding a greater understanding of the universe. It also provides many practical uses: new manufacturing techniques, consumer products, and the prospect of abundant energy.