THE STRUCTURE OF MATTER
CHAPTER 4
PHYSICAL SCIENCE
Vocabulary Words- Chapter 4 ( 12 words)
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Chemical bond
Chemical structure
Ionic bond
Covalent bond
Organic compounds
Polymer
Biochemical compound
Carbohydrate
Protein
amino acid
polar
non-polar
A. Compounds and Molecules
1.
Chemical bonds distinguish compounds from
mixtures
a.
b.
Chemical bond: the attractive force that holds
atoms or ions together
Mixtures are made of different substances placed
together
1. Each substance retains its own properties
2. A compound always has the same chemical
formula
a.
b.
A chemical formula shows the types and numbers of
atoms or ions making up the simplest unit of the
compound.
Compounds are always made of the same elements in
the same proportion.
1. H20: 2 Hydrogen and 1 Oxygen
3. Chemical Structure shows the bonding
within a compound
a.
b.
Chemical structure: the
arrangement of bonded
atoms or ions within a
substance
Many different
structural models
B. Ionic and Covalent Bonding
1.
Ionic Bonds
a. Ionic bonds: a bond formed by the attraction between
oppositely charged ions.
b.
Example: Na+ and Clc. The oppositely charged ions attract each other and form a
bond.
2. Covalent Bonds
a.
b.
Covalent bonds: a
bond formed when
atoms share one or
more pairs of electrons
Covalent bonds where
electrons are shared
equally are nonpolar
covalent bonds
1. Example: Cl2
c. Atoms do not always share electrons
equally
1.
2.
3.
An unequal sharing of electrons forms a polar
covalent bond
Example: H2O
One end has a positive charge, while the other end
has a negative charge
3. Organic and Biochemical Compounds
a.
b.
organic compounds: any covalently bonded
compound that contains carbon
Carbon atoms form four covalent bonds in organic
compounds
c. Polymers
1. polymer: a large organic
molecule made of many
smaller bonded units
d. Biochemical Compounds
1.
2.
Biochemical compounds: any organic compound that
has an important role in living things
Carbohydrate: any organic compound that is made of
carbon, hydrogen, and oxygen and that provides
nutrients to the cells of living things
3. protein: a biological polymer made of
bonded amino acids
4. Amino acid: any one of 20 different naturally
occurring organic molecules that combine to form
proteins