Chemistry of Life
Chapter 2 Sections 1 & 2
(pg 27-33)
Vocabulary
 Atom- The smallest unit of matter that can
not be broken down by chemical means.
 Element- A pure substance made of only
one kind of atom.
 Compound- A substance made of the
joined atoms of 2 or more different
elements
 Molecule- Group of atoms held together
by covalent bonds
 Ion- An atom or molecule that has gained
or lost one or more electrons
Vocabulary Cont.
 Cohesion- Attraction between substances of the
same kind
 Adhesion- Attraction between different substance
 Solution- A mixture in which one or more
substances are evenly distributed in another
substance
 Acid- pH = 0-6.9
 Higher concentration of H+ ions
 Lower concentration of OH- ions
 Base- pH = 7.1-14
 Lower concentration of H+ ions
 Higher concentration of OH- ions
pH Scale
 Standard of measurement of the
concentration of hydrogen ions (H+)
present in a solution.
 Range 0-14
Neutral 7
Acid 0-6.9
0
H+ Ions
Base 7.1-14
7
OH- Ions
14
Atom
 Proton
 Positive Charge
 Neutron
 No Charge
 Electron
 Negative Charge
Elements, Isotopes, Compounds
 More than 100 elements
 Isotopes- Atoms of an element that
contain different numbers of neutrons
 Carbon 12, Carbon 13, Carbon 14
 Sodium + Chloride = NaCl
 NaCl is table salt!!
 Hydrogen + Oxygen = H2O
 H2O is water!!
Bonds
 Chemical Bond
 A force that joins atoms
 Covalent Bonds
 Form when 2 or more atoms SHARE electrons to
form a molecule
 Hydrogen Bonds
 A WEAK chemical attraction between polar
molecules
 Ionic Bond
 Ions of opposite charge interact
Water
 70% of your body is made up of
water
 Water
 “Universal Solvent”
 Water is polar, it dissolves many polar
molecules
Solutions
 Solution
 A mixture in which one or more
substances are evenly distributed in
another substance
 Solute
 What gets dissolved
 Solvent
 What is doing the dissolving
Polar vs Nonpolar Molecules
 Polar Molecules
 Unequal distribution of electrical charge
 Dissolve well in water
 Ionic compounds and polar molecules
dissolve best in water
 Nonpolar Molecules
 Do not dissolve well in water
 Example: Oil and Water
 Water is more attracted to itself than the
oil
Acids & Bases
 Acid
 Compounds that form hydrogen ions
(H+) when dissolved in water
 Base/Alkaline
 Compounds that reduce the
concentration of hydrogen ions (H+) in a
solution
 Form hydroxide ions (OH-) when in water
Buffers
 Buffers help maintain pH levels in
living things
 Lemon + Household Ammonia
 More OH- than H+?
 Any base
 Antacid
 Hand Soap
 Household Ammonia
States of Matter
Some Characteristics of Gases, Liquids and Solids
gas
liquid
solid
assumes the shape
and volume of
its container
assumes the shape of the
part of the container
which it occupies
retains a fixed volume
and shape
compressible
not easily compressible
flows easily
flows easily
not easily
compressible
does not flow easily
Lime Juice
 Spencer and Veronica were having a lime eating
contest. They decided to see who could eat the
most limes in a minute without making the sour
face. Spencer ate 12 limes while Veronica could
only eat 4. A couple of hours later they both
noticed that they had heartburn, which is a painful
and burning sensation in the esophagus, just below
the breastbone usually associated with
regurgitation of gastric acid.
 Take an antiacid – Neutralize the acidic lime juices in
their stomaches.
 pH around 2-3
Acidic, Basic (alkaline) or Neutral
Hydrogen ions
Hydroxide ions
Neutral
Base
Acid