Download Matter

MATTER:
ELEMENTS AND COMPOUNDS
It matters.
It matters.
• Anything that has a mass and a volume
Close up view of atoms and their behavior
Animated images are from http://www.chem.purdue.edu/gchelp/
• Changing from one state to another is a
physical change
• If a new substance is formed it is a
chemical change
Images are from http://www.chem4kids.com
• The building blocks of Matter consist of Protons (+),
Electrons (-), and Neutrons (N)
Images are from http://www.chem4kids.com
• Consist of only one kind of atom
• Cannot be broken down into a simpler type of matter
by either physical or chemical means without
losing their identity
• Can exist as either atoms or molecules
• In the Earth’s crust, Oxygen is the most abundant
element (46.6%)
• Silicon is the second most abundant element (27.7%)
• Aluminum (8.1%), Iron (5.0%), Calcium (3.6%), Sodium
(2.8%), Potassium (2.6%), and Magnesium (2.1%)
complete the list of elements that account for about
98.5% of the total mass of the earth’s crust
• Aluminum, Iron, Oxygen, and Silicon make up about 88
percent of the earth's solid surface
• Water on earth’s surface and in the air as clouds and fog
are made of Hydrogen and Oxygen
• The air is 99 percent Nitrogen and Oxygen
• Hydrogen, Oxygen, and Carbon make up 97 percent of a
person
• Almost everything you see in this picture is made up of
just six elements: Hydrogen, Oxygen, Carbon, Nitrogen,
Aluminum, and Silicon
• Atoms of two or more different elements
chemically bound together
 Ex: H2O, NaCl, C6H12O6, CO2
• Can be broken down into elements again
through a chemical reaction
In the animation above, water (H2O) is a compound made of
Hydrogen and Oxygen.
Animated images and notes from http://www.chem.purdue.edu/gchelp/atoms/elements.html
• The properties of the elements that make up a
compound are often quite different from
the properties of the compound itself
• Sodium (Na) is a highly reactive metal
•
•
Chlorine (Cl) is a poisonous gas
Sodium Chloride (NaCl) is table salt
• Compounds are made of molecules
• A molecule is 2 or more atoms chemically bonded
• Water = 2 atoms of Hydrogen and one atom of
Oxygen = H2O
• A molecule is the smallest particle of a
compound that has all the properties of
that compound
• As all atoms of a certain element are alike, so are
molecules of a certain compound alike
• In the animation above, two nitrogen atoms
(N + N = N2) make one Nitrogen molecule .
• A shorthand way of representing compounds
• If chemical symbols are the letters, these are the words
• Ex: NH3 = ammonia
C3H7OH = rubbing alcohol
• Sometimes the formula represents a molecule of a single
element
• These are called diatomic molecules and this is how that
element is naturally found
• O2 = Oxygen
H2 = Hydrogen
Cl2 = Chlorine
• Subscripts are small numbers used in chemical formulas
• They are placed to the lower right of the chemical symbol
• Subscripts represent # of atoms of an element in the
compound
• CO2 = 1 atom of Carbon and 2 atoms of Oxygen
• H2SO4 = 2 atoms of Hydrogen, 1 atom of Sulfur and 4 atoms
of Oxygen
• Elements are pure substances that make
up all matter on earth
• The smallest piece of an element is an atom
• Compounds are things made of a
combination of elements
• The smallest piece of a compound is a molecule
• Atoms combine to form molecules