Download Compounds

Compounds
Standards 3.b.c.f. 6.a.b.c.
Topic 1: Compound Formation
Standards 3.b.f.
Compounds
—  A compound is a pure substance that
contains two or more elements.
—  Most of the matter around you is made of
compounds.
—  For example, water is a compound
made of two different elements. The
chemical formula for water is H2O, which
means water is made up of hydrogen and
oxygen atoms.
Representing Compounds
—  Compounds can be represented in many different ways.
Compounds
Chemical Bonds
—  All compounds are held together by chemical bonds.
—  A chemical bond is a force that holds atoms together
in a compound.
—  The bonding of two hydrogen atoms with an oxygen atom
makes the water compound H2O.
—  This compound has unique properties from its original
two elements. Hydrogen and oxygen are both gasses, but
when they bond together they form a liquid.
Compound Composition
—  You can use the periodic table of elements to identify the
different types of elements that make up a compound.
—  Sugar has the chemical
formula C6H12O6. Using
the periodic table it is clear
that sugar is made up of the
elements carbon (C),
hydrogen (H), and oxygen
(O).
What elements are these compounds made up of?
Think-Check
—  Hydrogen (H) and oxygen
(O) bond together to form
water (H2O). Why are the
properties of water different
from hydrogen and oxygen?
—  What is the name of the
indicated element in
the molecule shown?
A.  Water is a solution
B.  Water is an element
C.  Water is a compound
A.  Calcium
B.  Carbon
C.  Copper
Topic 2: Forming Solid Compounds
Standards 3.c.f.
Solid Structure
—  There are some compounds that form
a solid structure.
—  For example, the compound NaCl
(salt) combines with other salt
molecules to form a solid crystal
structure.
—  The compounds that make up the
solid structure have repeating
patterns that are held together by
chemical bonds.
Polymers
—  A polymer is a compound made up of many smaller compounds.
—  Some polymers include proteins, DNA, and polyethylene.
—  For example, proteins make up your hair, your skin, and your
muscles. Protein polymers are made up of many smaller amino
acid compounds.
—  The many smaller parts of the polymers are held together by chemical
bonds.
Think-Check
—  How has the following
solid formed?
A.  Many compounds have
bonded and formed
repeating patterns.
B.  Many compounds have
repeated.
C.  Many compounds
changed properties.
—  Sodium chloride (salt)
forms when sodium and
chlorine bond. What are
the chemical symbols for
the two elements found
in sodium chloride?
A.  S and C
B.  Sr and Cr
C.  Na and Cl
Topic 3: Compounds of Life
Standards 3.f. 6.a.b.c.
Elements of Life
—  There are six elements that make up nearly 100% of living things.
—  These elements are carbon, hydrogen, oxygen, nitrogen,
sulfur, and phosphorus.
Composition of the Human Body
Oxygen
Carbon
Hydrogen
Nitrogen
Other
Carbon Compounds
—  Most of the compounds that make up living things are
organic compounds.
—  An organic compound is a compound that contains the
element carbon.
—  Carbon is unique because it can form many bonds with
other carbon atoms and other elements.
Compounds of Life
—  Organic compounds found in living things include
carbohydrates, fats, proteins, and DNA.
—  Other important compounds for life include water and salt.
Think-Check
—  Which of the following
compounds is most
likely to be part of a
living organism?
A.  MoCl2
B.  BF3
C.  C6H12O6
—  What characteristic of
carbon makes it essential
to living things?
A.  Carbon bonds in may
ways to form chains.
B.  Carbon can exist as a
solid, liquid, or gas.
C.  Carbon forms crystal
structures under certain
conditions.