Draw this model now

elements, mixtures, compounds video:https://www.youtube.com/watch?v=yzGSLA68_Hw

• This is a model of what?

• What are the red objects? (label it now)

• What is the name of the blue region?

• What two objects make up the blue region?

• Everything that exists is made of matter (even the air you now breathe). So, what is matter?

• Matter is anything which has both mass and volume. Are ideas matter?

• Matter is made of atoms which can be arranged in almost infinite ways to make the world as we know it (brick houses?)

• Atoms are on the order of a trillionth of a meter in size: 10-10 meters

• Atoms are constantly moving in irregular-jerky like motion called Brownian motion (model?)

• So, though you may have a solid material, in fact at the atomic level atoms are moving quite vigorously but you cannot see/feel the motion!

I. Element (ie: oxygen, hydrogen, lead, gold, krypton):

A. exists as only one type of atom: it is, therefore a pure substance (This does not often occur in nature); gold necklace?

Oxygen is the most common pure element on Earth (occurs as a dioxide: O2 , what does “di” mean?)

B. cannot be broken down by chemical reactions: burning/acids/eating (but nuclear rxns: yes!)

C. There are some 118 elements (this # changes as we discover new elements), 90 of these are naturally occurring, 22 are synthetic (?)

D. two large groupings:

metals and

nonmetals (which is the larger group?)

E. they can ALL occur as different energy states: solid, liquid, gas or plasma: gold gas?

F. symbology:1. abbreviated by a unique letterwhich is capitalized, if there is a second letter it is lower case: Cuoxygen = Ohydrogen = Hhelium = Helead = Pb (?)gold = Au (?)NOTE: Latin is the basis for the symbol:dead language thus it does not change: world-wide use

79

196.9

What element is this andwhat is the easiest way to find it on the periodic table?Draw this now:

2. the atomic number defines the element:

it is unique: no other element has that number! (like DNA is to the living)

3. the atomic # also identifies the number of protons per atom (located in the nucleus).

So, atomic # = # protons per atom

G. each element has its own physical and chemical properties: called its own characteristic properties, thus

these characteristics properties can be used to identify and separate elements, such as the

temperature of a phase change to separate water from alcohol (distillation) or as a forensic scientist?

2. Mixture (ie: ocean, air, lemonade):A. two or more physically combined

substances (elements and/or compounds): NOT chemically combined! Thus, there are no bonds between substances: salt & pepper

B. not a pure substance (pure substance cannot be separated by physical means)

C. their individual substances retain their own characteristic properties, thus can use their c.p. to separate them: tap water, air?

D. use physical means to separate mixture: filter, dehydrate (salt water), density, sort (salt &

pepper)E. two types of mixtures: 1. homogeneous mixture: equal distribution of

each substance (sugar cookie): lemonade? 2. heterogeneous mixture: unequal

distribution of each substance (chocolate chip cookie): lemonade?

Mixture of colors:

Mixture or compound?Homo or heterogeneous?

3. Compound (ie: water, wood, most of what is around us!)A. most individual atoms of elements are unstable (reactive: like freshmen!), and thus want to chemically combine to form stable new substances (like seniors are) by creating:

chemical bonds (ie: magnets?)B. the new substance has new and different characteristic properties: H2O, NaCl, MgCl?C. atoms always combine in definite proportions: this is called a chemical formula:

1. 3H2O ?2. tells the # of molecules (3) and # of atoms (9)3. coefficient = # molecules:

three H2O molecules: H2O + H2O + H2O4. subscript (sub ?) = # atoms of only that atom:

H2 = two hydrogen atoms

3H2 = 6 atoms

Compound of table salt (NaCl):

D. two groups of compounds, based on how they combine:

1. molecular: atoms share electrons, ie: H2O

2. ionic: atoms gain or lose electrons, becoming a “charged atom”:

*gain e- and become negative (anion)

*lose e- and become positive (cation)

a. most are solids and soluble in water

b. ie: NaCl (table salt)