Chapter 2 Chemistry of Life

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Lynn English High School Science
Ms. Mezzetti
Modified from Modern Biology Textbook-Holt
• Define the term matter.
• Explain the relationship between elements and atoms.
• Draw and label a model of the structure of an atom.
• Explain how compounds affect an atom’s stability.
• Contrast covalent and ionic bonds.
Matter is
anything that
occupies space
and has mass.
Mass is the
quantity of
matter an
object has.
Elements are made
of a single kind of
atom and cannot be
broken down by
chemical means into
simpler substances.
Atoms are
composed of
protons, neutrons,
and electrons.
The Nucleus
Protons and neutrons
make up the nucleus of
the atom.
Protons are positively
charged particles.
Neutrons have no
charge (neutral).
• Electrons
– Electrons move about
the nucleus in orbitals.
– An orbital is a threedimensional region
around a nucleus that
indicates the probable
location of an electron.
Isotopes
Atoms of the same
element that have a
different number of
neutrons are called
isotopes.
• Ionic Bonds
– An ionic bond is
formed when one
atom gives up an
electron to another.
The positive ion is then
attracted to a negative
ion to form the ionic
bond.
Objectives
• Describe the physical properties of each state of matter.
• Describe the role of reactants and products in chemical
reactions.
Energy and Matter
• States of Matter
– Addition of energy
to a substance can
cause its state to
change from a
solid to a liquid
and from a
liquid to a gas.
Energy and Chemical
Reactions
• Reactants are substances that enter chemical reactions.
• Products are substances produced by chemical reactions.
Objectives
• Identify the roles of solutes and solvents in solutions.
• Differentiate between acids and bases.
Solutions
Solute + Solvent = Solution
Acids and Bases
• Acids
– Acidic solutions contain more hydronium ions than
hydroxide ions (H+)
• Bases
– Basic solutions contain more hydroxide ions than
hydronium ions (OH-)
• Buffers
– Buffers are chemicals that neutralize the effects of
adding small amounts of either an acid or a base to a
solution.
• pH
– Scientists have
developed a scale for
comparing the
relative
concentrations of
hydronium ions and
hydroxide ions in a
solution. This scale is
called the pH scale,
and it ranges from 0
to 14.
Name 3 parts of an atom
What are 3 states of matter
Differentiate covalent and ionic bonds
What makes up a solution
Differentiate reactants and products
Why is pH important to living organisms
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