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by Patty Bostwick-Taylor,
Florence-Darlington Technical College
Basic
Chemistry
2
PART A
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Matter and Energy
 Matter—anything that occupies space and has
mass (weight)
 Energy—the ability to do work
 Chemical
 Electrical
 Mechanical
 Radiant
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Composition of Matter
 Elements—fundamental units of matter
 96% of the body is made from four elements
 Carbon (C)
 Oxygen (O)
 Hydrogen (H)
 Nitrogen (N)
 Atoms—building blocks of elements
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Atomic Structure
 Nucleus
 Protons (p+)
 Neutrons (n0)
 Outside of nucleus
 Electrons (e-)
Figure 2.1
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Atomic Structure of Smallest Atoms
Figure 2.2
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Identifying Elements
 Atomic number—equal to the number of protons
that the atom contains
 Atomic mass number—sum of the protons and
neutrons
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Isotopes and Atomic Weight
 Isotopes
 Have the same number of protons
 Vary in number of neutrons
Figure 2.3
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Isotopes and Atomic Weight
 Atomic weight
 Close to mass number of most abundant
isotope
 Atomic weight reflects natural isotope
variation
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Radioactivity
 Radioisotope
 Heavy isotope
 Tends to be unstable
 Decomposes to more stable isotope
 Radioactivity—process of spontaneous atomic
decay
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Molecules and Compounds
 Molecule—two or more like atoms combined
chemically
 Compound—two or more different atoms
combined chemically
Figure 2.4
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Chemical Reactions
 Atoms are united by chemical bonds
 Atoms dissociate from other atoms when
chemical bonds are broken
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Electrons and Bonding
 Electrons occupy energy levels called electron
shells
 Electrons closest to the nucleus are most
strongly attracted
 Each shell has distinct properties
 The number of electrons has an upper limit
 Shells closest to the nucleus fill first
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Electrons and Bonding
 Bonding involves interactions between electrons
in the outer shell (valence shell)
 Full valence shells do not form bonds
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Inert Elements
 Atoms are stable (inert) when the outermost shell
is complete
 How to fill the atom’s shells
 Shell 1 can hold a maximum of 2 electrons
 Shell 2 can hold a maximum of 8 electrons
 Shell 3 can hold a maximum of 18 electrons
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Inert Elements
 Atoms will gain, lose, or share electrons to
complete their outermost orbitals and reach a
stable state
 Rule of eights
 Atoms are considered stable when their
outermost orbital has 8 electrons
 The exception to this rule of eights is Shell 1,
which can only hold 2 electrons
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Inert Elements
Figure 2.5a
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Reactive Elements
 Valence shells are not full and are unstable
 Tend to gain, lose, or share electrons
 Allow for bond formation, which produces
stable valence
Figure 2.5b
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Chemical Bonds
 Ionic bonds
 Form when electrons are completely
transferred from one atom to another
 Ions
 Charged particles
 Anions are negative
 Cations are positive
 Either donate or accept electrons
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Ionic Bonds
Na
Cl
Sodium atom (Na)
(11p+; 12n0; 11e–)
Chlorine atom (Cl)
(17p+; 18n0; 17e–)
+
–
Na
Cl
Sodium ion (Na+)
Chloride ion (Cl–)
Sodium chloride (NaCl)
Figure 2.6
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Ionic Bonds
Na
Cl
Sodium atom (Na)
(11p+; 12n0; 11e–)
Chlorine atom (Cl)
(17p+; 18n0; 17e–)
Figure 2.6, step 1
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Ionic Bonds
Na
Cl
Sodium atom (Na)
(11p+; 12n0; 11e–)
Chlorine atom (Cl)
(17p+; 18n0; 17e–)
Figure 2.6, step 2
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Ionic Bonds
Na
Cl
Sodium atom (Na)
(11p+; 12n0; 11e–)
Chlorine atom (Cl)
(17p+; 18n0; 17e–)
+
–
Na
Cl
Sodium ion (Na+)
Chloride ion (Cl–)
Sodium chloride (NaCl)
Figure 2.6, step 3
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Chemical Bonds
 Covalent bonds
 Atoms become stable through shared
electrons
 Single covalent bonds share one pair of
electrons
 Double covalent bonds share two pairs of
electrons
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Examples of Covalent Bonds
Figure 2.7a
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Examples of Covalent Bonds
Figure 2.7b
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Examples of Covalent Bonds
Figure 2.7c
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Polarity
 Covalently bonded
molecules
 Some are non-polar
 Electrically
neutral as a
molecule
 Some are polar
 Have a positive
and negative
side
Figure 2.8
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Chemical Bonds
 Hydrogen bonds
 Weak chemical bonds
 Hydrogen is attracted to the negative portion
of polar molecule
 Provides attraction between molecules
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Hydrogen Bonds
Figure 2.9
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Patterns of Chemical Reactions
 Synthesis reaction (A + BAB)
 Atoms or molecules combine
 Energy is absorbed for bond formation
 Decomposition reaction (ABA + B)
 Molecule is broken down
 Chemical energy is released
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Synthesis and Decomposition Reactions
Figure 2.10a
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Synthesis and Decomposition Reactions
Figure 2.10b
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Patterns of Chemical Reactions
 Exchange reaction (AB + CAC + B)
 Involves both synthesis and decomposition
reactions
 Switch is made between molecule parts and
different molecules are made
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Patterns of Chemical Reactions
Figure 2.10c
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Biochemistry: Essentials for Life
 Organic compounds
 Contain carbon
 Most are covalently bonded
 Example: C6H12O6 (glucose)
 Inorganic compounds
 Lack carbon
 Tend to be simpler compounds
 Example: H2O (water)
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Important Inorganic Compounds
 Water
 Most abundant inorganic compound
 Vital properties
 High heat capacity
 Polarity/solvent properties
 Chemical reactivity
 Cushioning
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Important Inorganic Compounds
 Salts
 Easily dissociate into ions in the presence of
water
 Vital to many body functions
 Include electrolytes which conduct electrical
currents
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Dissociation of a Salt in Water
Figure 2.11
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Important Inorganic Compounds
 Acids
 Release hydrogen ions (H+)
 Are proton donors
 Bases
 Release hydroxyl ions (OH–)
 Are proton acceptors
 Neutralization reaction
 Acids and bases react to form water and a salt
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pH
 Measures relative
concentration of
hydrogen ions
 pH 7 = neutral
 pH below 7 = acidic
 pH above 7 = basic
 Buffers—chemicals
that can regulate pH
change
Figure 2.12
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Important Organic Compounds
 Carbohydrates
 Contain carbon, hydrogen, and oxygen
 Include sugars and starches
 Classified according to size
 Monosaccharides—simple sugars
 Disaccharides—two simple sugars joined
by dehydration synthesis
 Polysaccharides—long-branching chains
of linked simple sugars
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Carbohydrates
Figure 2.13a–b
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Carbohydrates
Figure 2.13c
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Carbohydrates
Figure 2.14
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Important Organic Compounds
 Lipids
 Contain carbon, hydrogen, and oxygen
 Carbon and hydrogen outnumber oxygen
 Insoluble in water
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Lipids
 Common lipids in the human body
 Neutral fats (triglycerides)
 Found in fat deposits
 Composed of fatty acids and glycerol
 Source of stored energy
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Lipids
Figure 2.15a
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Lipids
 Common lipids in the human body (continued)
 Phospholipids
 Form cell membranes
 Steroids
 Include cholesterol, bile salts, vitamin D,
and some hormones
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Lipids
Figure 2.15b
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Lipids
 Cholesterol
 The basis for all steroids made in the body
Figure 2.15c
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Important Organic Compounds
 Proteins
 Made of amino acids
 Contain carbon, oxygen, hydrogen,
nitrogen, and sometimes sulfur
Figure 2.16
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Proteins
 Account for over half of the body’s organic matter
 Provide for construction materials for body
tissues
 Play a vital role in cell function
 Act as enzymes, hormones, and antibodies
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Proteins
 Amino acid structure
 Contain an amine group (NH2)
 Contain an acid group (COOH)
 Vary only by R groups
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Proteins
 Fibrous proteins
 Also known as
structural proteins
 Appear in body
structures
 Examples include
collagen and
keratin
 Stable
Figure 2.17a
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Proteins
 Globular proteins
 Also known as
functional proteins
 Function as
antibodies or
enzymes
 Can be denatured
Figure 2.17b
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Enzymes
 Act as biological catalysts
 Increase the rate of chemical reactions
Figure 2.18a
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Enzymes
Figure 2.18b
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Important Organic Compounds
 Nucleic Acids
 Provide blueprint of life
 Nucleotide bases
 A = Adenine
 G = Guanine
 C = Cytosine
 T = Thymine
 U = Uracil
 Make DNA and RNA
Figure 2.19a
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Nucleic Acids
 Deoxyribonucleic acid
(DNA)
 Organized by
complimentary
bases to form
double helix
 Replicates before
cell division
 Provides
instructions for
every protein in the
body
Figure 2.19c
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Important Organic Compounds
 Adenosine triphosphate (ATP)
 Chemical energy used by all cells
 Energy is released by breaking high energy
phosphate bond
 ATP is replenished by oxidation of food fuels
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Adenosine Triphosphate (ATP)
Figure 2.20a
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Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Energy liberated during
oxidation of food fuels
used to regenerate ATP
Figure 2.21
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Membrane
protein
P
Solute
(a) Transport work
ATP
Figure 2.21, step 1
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Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ATP
ADP
+
P
Figure 2.21, step 2
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ATP
Relaxed
muscle cell
(b) Mechanical work
Figure 2.21, step 3
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ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
Figure 2.21, step 4
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ATP
X
P
+ Y
Reactants
(c) Chemical work
Figure 2.21, step 5
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ADP
+
P
ATP
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Figure 2.21, step 6
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Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Figure 2.21, step 7
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Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Energy liberated during
oxidation of food fuels
used to regenerate ATP
Figure 2.21, step 8
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The
End
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