Chemistry, Part I
Human Anatomy and Physiology I
Oklahoma City Community College
Dennis Anderson
Matter
• Anything that takes up space and has mass
Element
One Kind of Matter
•Carbon
•Nitrogen
•Oxygen
•Hydrogen
Compound
Two or more elements combined together
•Carbon Dioxide
•Sodium Chloride
•Water
Atom
Minute particles that make up matter
Atomic Model
Proton
Neutron
Electron
Subatomic Particles
Proton
Charge
Positive
Neutron
Neutral
Electron
Negative
Atomic
Mass Unit
One
One
Near Zero
Atomic Number
Number of Protons
• Hydrogen = 1
• Carbon = 6
• Oxygen = 8
Protons = Electrons
Protons
Electrons
Hydrogen
1
1
Carbon
6
6
Oxygen
8
8
Atomic Mass Number
Number of Protons and Neutrons
Hydrogen
• Atomic Number = 1
• Atomic Mass Number = 1
Hydrogen Atom
First Energy Level
Two Electrons Maximum
First Energy Level
Second Energy Level
Eight Maximum
Second Energy
Level
Third Energy Level
Stable with Eight Electrons
Third
Energy
Level
Carbon
• Atomic Number = 6
• Atomic Mass Number = 12
Carbon Atom
6+ 60
Oxygen
• Atomic Number = 8
• Atomic Mass Number = 16
Oxygen Atom
8+ 80
Isotope
An atom of an element with a
different number of neutrons than
other atoms of the same element
Isotopes of Carbon
Each Carbon has 6 protons
•
•
•
•
Carbon 12
Carbon 13
Carbon 14
Carbon 15
6 Neutrons
7 Neutrons
8 Neutrons
9 Neutrons
Atomic Weight
Average of the mass numbers of all
the isotopes of an element
Atomic Weight of Carbon = 12.01
Average Mass Numbers of Carbon
12,13,14 and 15
Radioactive Isotopes
• Break down at a constant rate
–Half Life
Uses for Isotopes
• Carbon 14 for dating the age of
skeletons
• PET scan
• Iodine isotope for thyroid studies
• Cobalt isotope for cancer treatment
Sodium
• Atomic Number = 11
• Atomic Mass Number = 23
Sodium Atom
11+
120
Chlorine
• Atomic Number = 17
• Atomic Mass Number = 35
Chlorine Atom
17+
180
11+
120
17+
180
Sodium Ion
+
Na
Lost an Electron
11+
120
Chloride Ion
Cl
Gained an Electron
17+
180
Ion
An Atom or Molecule With a Charge
Formed by
-Gaining electrons
-Losing electrons
Ionic Bond
Chemical bond formed by the
attraction of opposite charges
+
Na
Cl
Chemical Bond
Force that holds atoms
together in a molecule
Anion: Ion with a - Charge
Cation: Ion with a + Charge
• Regulate water balance
• Regulate acid-base balance
• Form essential minerals
Ions
• Anions
– Cl– OH– HCO3-
• Cations
–
–
–
–
–
Na+
K+
Ca++
Mg++
H+
Free Radical
8+ 80
Antioxidant
Molecule
Two or More Atoms (Ions) Joined
Together
+
Na
Cl
Sodium Chloride
Hydrogen Atoms
Electrons Shared
Covalent Bond
Formed by Sharing Electrons
Covalent Bond
H H
Diatomic Molecule
Two Atoms
Four Covalent Bonds in Carbon
Structural Formula
H
H C H
H
Carbon Chain
H H H H H H
H C C C C C C H
H H H H H H
Water Molecule
+
+
Polar Molecule
Properties of Water
•
•
•
•
•
•
•
•
•
Polar
Adhesion
Cohesion
Capillary action
High surface tension
High specific heat
High heat of vaporization
Solvent
Chemical reactivity
Water Molecule
+
+
Some Hydrogens Leave
+
+
Electron Stays with Water
Electron
+
+
Hydroxide Ion
Hydrogen Ion
+
+
Water
HOH
+
H
OH
Water
The number of
+
H
Equals the
number of
OH
Acid
Chemical That Releases
Excess Hydrogen Ions
HCl
+
H
+
Cl
Base
Chemical That Releases
Excess Hydroxide Ions
NaOH
+
Na
+
OH
pH Scale
0
1 2 34 5 6
+
H
7
OH
8 9 10 11 1213
14
0
1 2 34 5 6
7
8 9 10 11 1213
14
Hydrogen Ions =Hydroxide Ions
0
1 2 34 5 6
Acid
7
8 9 10 11 1213
Base
14
Stomach Skin Blood
0
1 2 34 5 6
7
8 9 10 11 1213
14
End of Part I