Nature

1
Nature
Nature - Largely made of 2 things. Energy - the
ability to produce heat or do work Matter
Anything that has mass and occupies space.
2
Observe Nature Law
Laws of Conservation of Energy Energy is never
created or destroyed, but can be transformed to
other forms, or transferred to other objects Law
of Conservation of Matter matter is never
created or destroyed, but can be rearranged into
different forms, or converted to
Energy Contradiction? - when matter is converted
to energy it seemingly disappears Dynamite
explosion vs. Nuclear Explosion Nuclear Fusion
and the Sun Emc2
3
Phases of Matter
Plasma - particles are moving so rapidly they
blur and break into charged (ionized) particles
(pieces break off) Gas - particles are not
connected to each other and in constant rapid
random motion (like several rubber balls bouncing
around) Liquid - particles loosely connected but
are free to flow past each other or
separate Solid - particles are locked to each
other in a rigid crystal lattice with a regular
pattern. They vibrate in space. Einstein Bose
Condensate - theoretical phase of matter where
all particle motion has stopped. Particles
arent even vibrating. Forms a new probability
cloud state of matter. Does not exist in
nature. Considered to be absolute zero.
Coldest possible temperature. Zero heat.
Measure to be -456 F, -273 C or 0 Kelvin.
4
Elements Compounds
Pure Substance ? Matter that has a fixed
composition and distinct properties. All
substances are made up of either elements or
compounds or a combination of the two. Elements ?
All atoms are the same, i.e. Oxygen (O2), Gold
(Au), Silicon (Si) and Diamond (C). Made of a
single type of atom. You should memorize the
elemental symbols and names 1-20 Compounds ?
Contains more than one type of atom that are
chemically attached (bonded), but all molecules
are the same, i.e. Water (H2O), Ethanol (C2H6O),
Quartz (SiO2), Sodium Chloride (NaCl). All
compounds follow the law of constant
composition. Water is the same formula (H2O)
everywhere Nothing else can be water
5
Periodic Table
6
Ne
N2
SO3
Mixture
7
Unique Properties and Characteristics
Atom The smallest stable building block of
matter. Made up of protons, neutrons
electrons. (H, O, Na, Cl) Molecule Groups of
atoms held together with a specific connectivity
and shape.(0, O2, O3, NaCl)
8
Unique Properties and Characteristics
Combination-some compounds are combinations of
the two, and therefore can exhibit properties of
both substances Composition tells us the types of
atoms that are present in a compound and the
ratio of these atoms (for example H2O, H2O2).
Structure tells us which atoms are chemically
attached (bonded) to each other, how far apart
they are, and the shape of the molecule.
(C6H12O6)
9
Mixtures
Mixture ? Have variable composition and can be
separated into component parts by physical
methods. Mixtures contain more than one kind of
particle, and their properties depend on the
relative amount of each component present in the
mixture.
10
Mixtures
Two or more elements or compounds that are
physically mixed, but not chemically attached
(bonded). A combination of the two. Some
mixtures you can see there are 2 or more
substances Cereal and Milk, gravel, Soapy
water Some mixtures you cannot see there are 2 or
more substances Steel, Kool-Aid, Salt Water, Air
11
Homogeneous Heterogeneous Mixtures
Homogeneous Mixture ? Composition and properties
are uniform. Sometimes called a solution. You
cant see 2 substances Air principle components
include O2, N2 CO2 Kool-Aid principle
components are sugar and water Steel solid
solution of Fe and C Ruby solid solution of
Al2O3 and Cr2O3 Heterogeneous Mixture ?
Composition and properties are non-uniform. You
can see two or more substances Chocolate Chip
Cookie Chocolate, Dough, etc. Concrete
Cement, Rocks, etc. Vomit Depends upon
previous intake of food and drink
12
(No Transcript)
13
Complete Description of Matter
Individually, neither Classifications or Phases
of Matter offer a complete picture of a
substance. Solid - what do aluminum, steel and
ice have in common? Homogeneous Mixture - what do
Kool-Aid and air have in common? You use a
combination of the two systems to better describe
a substance Aluminum solid element Ice
solid compound Steel solid homogenous
mixture Kool-Aid liquid homogenous
mixture Air Gaseous homogenous mixture
14
Chemical and Physical Properties
Physical Properties ? The identifying
characteristics of matter. Some properties can
be readily measured with our senses, such as odor
and color, instruments are needed to measure
other properties, such as electrical resistivity,
compressibility, hardness, melting point, etc.
The original substances are unchanged. Mixtures
are a physically combined substance, so can be
physically separated. Processes to separate a
heterogeneous mixtures Filtration (dirty water,
sizes of rock) Processes to separate a
homogeneous mixtures Distillation (salt and
water) Crystallization (hard tack
candy) Chromatography (our lab)
15
Chemical and Physical Properties
Chemical Properties ? Describe the reactivity of
a substance toward other substances. Due to a
rearrangement of bonds. A new substance is
formed. Examples include Ethanol burns in air
(reacts with oxygen in the air) Sodium reacts
vigorously with water Corrosion of metal parts
(rust) Trinitrotoluene (TNT) is
explosive Chemical Processes to change identity
of substance Electrolysis (our
lab) Rusting Burning
16
Ethanol Stoichiometry C2H6O Melting Point
-115 ºC Boiling Point 78 ºC Density 0.79
g/cm3 Chemical Prop. Intoxicating
Dimethyl Ether Stoichiometry C2H6O Melting
Point -140 ºC Boiling Point -24 ºC Density
Gas Chemical Prop. Intermediate
Ethylene Glycol Stoichiometry C2H6O2 Melting
Point -16 ºC Boiling Point 197 ºC Density
1.11 g/cm3 Chemical Prop. Toxic
17
Evidence of a Chemical Change
Chemical Change ? the particles in a compound
break apart from their current chemical
attachments (bonds) and rearrange to form new
attachments. Either to new and different
elements or in new amounts of attachments.
Bubbles - (baking soda in vinegar, or bubbles in
electrolysis) Change in temperature - (heat given
off in a burning reaction) Formation of a
precipitate - (our lab example) Sometimes changes
in appearance - color, sound, texture, rot
18
Chemical Reactivity
2H2(g) O2(g) ? 2H2O(g)