The Science of Chemistry
Before chemistry there was…..
Alchemy
Alchemy:A medieval science and philosophy
aiming to achieve:
1. Transmutation of base metals (like lead) into gold
Alchemy
2. Discovery of a universal cure for disease
Alchemy
3. Discovery of a way to prolong life
Has modern science achieved these things?
Wealth for all?
Cure for disease?
Prolonged life?
Why is Gold valuable?
• Rare
• Pretty
• Soft, easy to shape
• Resists corrosion
• Chemically unreactive
The science that studies the
structure,
composition,
and properties
of substances
and their transformations
(Webster)
What are the simplest substances?
• The ELEMENTS ( only about 90 occur naturally, 114 discovered)
• Listed in the Periodical Table
• Basic building blocks for all other more complex substances (compounds) found in the universe
Abundance of common elements in the Universe
• 60% Hydrogen H element #1
• 37% Helium He element #2
• 3% elements # 3-90
Abundance of elements on Earth (crust and atmosphere)
• 35% iron
• 30 % oxygen
• 15 % silicon
• 13% Magnesium
• 2.4% nickel
• 4.6% others
Origin of the Elements
Big Bang
• 15-20 billion years ago• Matter and energy scatter, expand, and
cool• Matter condenses to form galaxies,
Element Hydrogen forms• Stars form in galaxies. In stars, H fuses to
form Helium and energy• More fusion allows heavier elements to
form
We are all star dust……
Matter
Anything that has mass and takes up space (volume)
What is NOT matter???
Classification of Matter
Matter
Can it be separated by physical means?
If yes….
Then you have a Mixture
Physical ways to separate a mixture
• Filtering
(particle size)
• Distillation
(boiling point)
(dissolved solid)
Physical ways to separate a mixture
• Chromatography
(attraction to paper)
Is the mixture uniform throughout?
• IF yes, it is HOMOGENEOUS
If no, then the mixture is Heterogeneous
Homogeneous vs. Heterogeneous mixtures
MatterCan it be separated by physical means?
MixtureIs it uniform throughout?
Substance
HomogeneousGatoradeBronzeBrass
Homogenized beverages
HeterogeneousDirt
Sea shellsRocky road ice cream
Non-homogenized beverages
YES NO
YES NO
If matter can NOT be separated by physical means….
It is a SUBSTANCE
If the substance can’t be broken down, it is an ELEMENT
Elements are made of only one type of atom
Ex. Aluminum, carbon, oxygen
SUBSTANCEIf the substance CAN be broken down, it is a
COMPOUND, made of two or more different kinds of atoms chemically bonded together.
Ex. Water (2 Hydrogens and 1 oxygen)
MatterCan it be separated by physical means?
MIXTUREIs it uniform throughout?
SUBSTANCECan it be broken down?
HomogeneousGatoradeBronzeBrass
Homogenized beverages
HeterogeneousDirt
Sea shellsRocky road ice cream
Non-homogenized beverages
COMPOUNDWATER H20SALT NaCl
ELEMENTAluminum
Graphite (Carbon)
YES NO
YES NO Yes NO
ELEMENTS can be….
• MONATOMIC : single atoms Al
• DIATOMIC : two of the same atom bonded together in pairs O2
• POLYATOMIC: three or more of the same atom bonded together O3
7 Diatomic Elements
Particles of Matter
Review
What is……
MATTER
SUBSTANCE
MIXTURE
ELEMENT
COMPOUND
HETEROGENEOUS VS. HOMOGENEOUS
CHEMISTRY: THE STUDY OF MATTER
Did you know that……..
One of the most popular “foods” in the United States is an entirely SYNTHETIC (man-made) mixture.
Can you guess what it is?
SODA
The average person consumes 40 GALLONS (!)
of soda each year
Mixture:carbonated watersweetener, acids,flavorings, caffeine
States of Matter
GAS LIQUID SOLID
Physical Properties of Matter
The properties of a substance that can be demonstrated without changing the
composition of the substance
Size (length, volume)
Density
Mass
Color
Physical Properties
Melting Point
Ex. Ice (solid water) starts to melt to liquid water at 0 degrees Celsius
Boiling Point
Ex. Water boils into steam at 100 degrees Celsius
Physical Properties
Malleability: can be pounded into a new shape without breaking
Metals are malleable
Physical Properties
Iron is malleable
Fe
Physical Properties
Ductility
Can be pulled into long wires without breaking
Metals are ductile
Physical Properties
Crystal Shape
Reflects the regular arrangement of atoms in the solid
Physical ChangeA change in the sample of matter that does
not result in a NEW substance:
Phase Changes
Changes in shapeSolid liquid gas
Chemical Properties of Matter
How matter behaves when it changes into a NEW substance.
EX. Iron rusts silver tarnishes
Milk sours sugar ferments
eggs rot leaves turn
paper burns
Chemical Change
Substance changes into a NEW substance.
This change is often an irreversible and permanent change in composition
Burning
Tarnishing
Rusting
Oxidizing
Chemical Reaction
Chemical changes mean a chemical reaction has occurred
REACTANTS PRODUCTSold substances become new substances
Sodium + Chlorine sodium chloride (table salt)
Na + CL NaCL
Test Review
• Know names and symbols of common elements
Name SymbolAs SodiumCa IronMn TinCu GoldK Lead
Test Review
Matter
Classify the following samples of matter
Classify the following samples of matter
Classify the following samples of matter
Classify the following samples of matter
Classify the following samples of matter
Classify the following samples:
Classify the particles of matter
Identify the following changes as Physical or Chemical
Identify the following changes as Physical or Chemical
Identify the following changes as Physical or Chemical
Identify the following changes as Physical or Chemical
Identify the following changes as Physical or Chemical
Fe
Identify the following changes as Physical or Chemical
Identify the following changes as Physical or Chemical
Periodic Table Review
1. Elements are arranged according to______
2. Vertical columns are called________3. Horizontal rows are called ________4. There are ______ periods in the table5. Most elements are classified as _____6. Where are the transition metals?7. What are the metalloids?
Periodic Table Review
1. Describe 3 properties of metals
2. Describe 2 properties of non metals
3. Group 2 metals are called____________
4. Group 17 non metals are called _______
5. What two elements are liquid at room temperature?
6. How can you tell if a compound contains a transition metal?