Pure SubstancesA sample of matter that has definite

chemical and physical properties.

Elementspure substance that cannot be separated into simpler substance by physical or chemical means.

ElementsIn 1813, a system of

representing elements with symbols was introduced. Each symbol consists of

one or two letters. Two letters are needed for

a chemical symbol when the first letter of that element’s name has already been used.

Common ElementsAluminumAluminum AlAl

BromineBromine BrBr

CalciumCalcium CaCa

CarbonCarbon CC

GoldGold AuAu

HeliumHelium HeHe

HydrogenHydrogen HH

NitrogenNitrogen NN

CompoundsPure substance composed of two or more

different elements joined by chemical bonds.

Made of elements in a specific ratio that is always the sameHas a chemical formulaCan only be separated by chemical means, not physically

CompoundsCompounds are

also pure substances.

Water is a compound.

Water can be broken down into simpler substances – hydrogen and oxygen.

MixturesA combination of two or more pure

substances that are not chemically combined.

substances held together by physical forces, not chemical

No chemical change takes place Each item retains its properties

in the mixture They can be separated physically

Chem4kids.com

Is it uniform throughout?If the answer is yes, the matter is

homogeneous (looks the same throughout).That leads us to another question.

Homogeneous MixturesA mixture that appears to be the same throughout.

It is “well mixed.”The particles that make up the mixture are very small and not easily recognizable.

Examples of homogeneous mixtures

Milk, toothpaste, and mayonnaise are homogeneousmixtures.

SolutionsA solution is a type of homogeneous

mixture formed when one substance dissolves in another.

It is the best mixed of all mixtures.A solution always has a substance that is

dissolved and a substance that does the dissolving.

The substance that is dissolved is the solute and the substance that does the dissolving is the solvent.

Ocean water is a solution

Water as a solventMany liquid solutions contain water as the

solvent.Ocean water is basically a water solution that

contains many salts.Body fluids are also water solutions.

The universal solvent: Water

SOLUTIONS HAVE 2 PARTSSOLUTE – The substance being

dissolved

SOLVENT- The substance doing the dissolving

sugar=solute Water = solvent

Types of solutions

GasGas GasGas Air (oxygen in nitrogen)Air (oxygen in nitrogen)

GasGas LiquidLiquid Soda water (carbon dioxide Soda water (carbon dioxide in water)in water)

SolidSolid LiquidLiquid Ocean water (salt in water)Ocean water (salt in water)

Solute Solvent Example

SolidSolid SolidSolid Gold jewelry Gold jewelry (copper in gold)(copper in gold)

Metals dissolved in metals are called

alloys.

Brass is an alloy of copperand zinc.

Stainless steel is a mixtureof iron and chromium.

Is it uniform throughout?If the answer is no, the matter is a

heterogeneous mixture.Considered the “least mixed.”Does not appear to be the same throughout.Particles are large enough to be seen and to be

separated from the mixture.

Examples of heterogeneous mixturesSand and pebblesOil and waterPowdered iron and powdered sulfur

Granite is a heterogeneous mixture.

COLLOID – a liquid mixture - can be considered a homogeneous and sometimes heterogeneous mixture ex: milkSUSPENSION – a liquid mixture - heterogeneous -ex: Italian dressing

ColloidsIn a colloid the

particles are mixed together but not dissolved.

The particles are relatively large and are kept permanently suspended.

0

20

40

60

80

100

1st

Qtr

2nd

Qtr

3rd

Qtr

4th

Qtr

East

West

North

ColloidsA colloid will not

separate upon standing.

The particles are constantly colliding, and this allows a colloid to scatter light – thus colloids often seem cloudy.

Examples of homogeneous mixtures

Milk, toothpaste, and mayonnaise are homogeneous

mixtures. THESE ARE EXAMPLES OF COLLOIDS

Mixtures vs. Compounds

http://www.bbc.co.uk/schools/ks3bitesize/science/chemistry/elements_com_mix_6.shtml

Can you identify the following?You will be shown a series of photos. Tell if each

photo represents an item composed of an element, compound, or mixture.

Review:An element contains just one type of atom. A compound contains two or more different

atoms joined together. A mixture contains two or more different

substances that are only physically joined together, not chemically.A mixture can contain both elements and

compounds.

Element, Compound, or Mixture?Rocks

Element, Compound, or Mixture?Rocks

Element, Compound, or Mixture?Copper

Element, Compound, or Mixture?Copper

Element, Compound, or Mixture?Jelly Beans

Element, Compound, or Mixture?Jelly Beans

Element, Compound, or Mixture?Table Sugar

Element, Compound, or Mixture?Table Sugar

Element, Compound, or Mixture?Diamond

Element, Compound, or Mixture?Diamond

Element, Compound, or Mixture?Tea

Element, Compound, or Mixture?Tea

Element, Compound, or Mixture?Salt

Element, Compound, or Mixture?Salt

Element, Compound, or Mixture?Neon Gas

Element, Compound, or Mixture?Neon Gas

Element, Compound, or Mixture?Salad

Element, Compound, or Mixture?Salad

Element, Compound, or Mixture?Pure Water

Element, Compound, or Mixture?Pure Water

Element, Compound, or Mixture?Aluminum

Element, Compound, or Mixture?Aluminum

Element, Compound, or Mixture?Lemonade

Element, Compound, or Mixture?Lemonade

Element, Compound, or Mixture?Silver

Element, Compound, or Mixture?Silver

Element, Compound, or Mixture?Sand

Element, Compound, or Mixture?Sand

Which is:1)A pure compound2)Mixture of a compound and an element3) Mixture of elements4) Mixture of 2 different elements

Matter ElementMixtureCompoundHomogeneousHeterogeneousSolution ColloidSuspensionCopperKryptonWaterCarbon dioxideMountain dewMixed nutsVinegarAlloy- mixture of 2 metals joined together

NotesDetailed notes are located at:http://www.middleschoolscience.com/elements-compounds-mixtures-notes-isn.pdf

Flow Chart:http://www.middleschoolscience.com/matter-flow-chart-isn.pdf