atom the “smallest piece” of matter that still keeps all the properties of the element (we will...

Atom

The “smallest piece” of matter that The “smallest piece” of matter that still keeps all the properties of the still keeps all the properties of the

elementelement(we will talk about properties later)(we will talk about properties later)

All matter is composed of atomsAll matter is composed of atoms

AtomHave we ever seen atoms?

Yes – ever since the invention of the scanning tunneling electron microscope in 1981 by Nobel Laureates Gerd Binnig and Heinrich Rohrer

Platinum atoms

Molecule

Another “smallest piece” of matter – Another “smallest piece” of matter – but are made of two or more atoms.but are made of two or more atoms.

All matter is composed of moleculesAll matter is composed of molecules

Molecule

Matter -

Anything that has mass and Anything that has mass and takes up spacetakes up space

Pure Substance: is either an

ElementElementor aor a

CompoundCompound

Element-

Has only one kind of atom, Has only one kind of atom, found on the periodic tablefound on the periodic table

Examples of Elements

Anything on the Anything on the periodicperiodic table table

H He

O Ne

K Ar

N Kr

C Xe

Ca Rn

Compound -

Substance with two or more Substance with two or more kinds of atoms bound kinds of atoms bound

togethertogether

Example: Water

The elements hydrogen and The elements hydrogen and oxygen combineoxygen combine

Example : Salt

The elements sodium and The elements sodium and chloride combine (NaCl)chloride combine (NaCl)

Mixture – is a impure substance made of two or more

things mixed together

Can be separated by Can be separated by physical means, physical means,

Homogeneous mixture-

Evenly mixed mixture

Sometimes called a solution

Examples of solutions

Salt WaterSalt Water

Rubbing AlcoholRubbing Alcohol

Heterogeneous mixture-

Unevenly mixed mixtureUnevenly mixed mixture

*Different materials can be seen

Examples:Italian dressing, Concrete, PizzaItalian dressing, Concrete, Pizza

Colloids-

A A heterogeneous heterogeneous mixture that mixture that never settles never settles and scatters and scatters

lightlight

Examples: gelatin, whipped cream

Examples: milk, fog

Suspension-

A type of mixture in which A type of mixture in which visible particles settlevisible particles settle

Examples: muddy water,

Italian dressing,

snow globes