Atoms Ions

1
Cation Humor
2
A Little ReviewMolecular Compounds

• Molecular compounds are charge neutral.

H
water
ammonia
methane
What are the trivial names of these common
molecular compounds?
3
Salts

• Salts are composed of a cation and an anion to
  give a neutral compound.

CaCl2
calcium chloride
NH4ClO4
ammonium perchlorate
Al2O3
aluminum oxide
Name these salts by combining the cation and
anion names.
4
Salts

• Why is the formula for aluminum oxide
• Al2O3
• and not
• AlO?

5
Constructing Ions

• Construct and name at least 10 neutral compounds
  that can be formed from the following list of
  atoms.
• H O S Na Ca Cr Fe In Pb
• Divide up the activity work on cations or anions.

6
Constructing Ions

• Combine cations and anions to make neutral
  compounds.
• Determine the formula and name of each compound.
• Use each cation or anion only once in making
  various compounds.
• Identify and name any molecular, neutral compound
  that can be formed.

7
Problem Set

• Twenty Compounds Problem Set

8
Twenty CompoundsProblem Set

• Due Thursday
• Problem set format
• Include your name and box number
• Staple the problem set on top of your answers
• One side of page for answers is preferable
• Staple questions and answers together
• No ragged edges make it look neat!

9
Atoms and Ions

• Edward A. Mottel
• Department of Chemistry
• Rose-Hulman Institute of Technology

10
Resources Available

• Reading assignment
• Zumdahl Chapter 2.1-2.4, 2.6

11
Historical View of the Atom

• Smallest piece of matter (Democritus, Greek
  philosopher)

• Smallest particle of an element that can exist
  either alone or in combination (Websters
  dictionary)

• Smallest particle which exhibits the
  characteristic chemical properties of an element.

12
Matter

• An aggregate of material particles, capable of
  being located in space and time, and possesses
  the inherent property of inertia.
• Elements, compounds, mixtures

13
Elements

• A substance which cannot be divided into simpler
  substances.

Is a hydrogen atom an element?
Is a hydrogen molecule an element?
14
Compound

• Pure substance consisting of elements, all bonded
  together in a similar fashion.
• The composition is precisely defined.
• The ratio of elemental masses is always the same.

Is water a compound?
Is salt water a compound?
15
Mixtures

• Matter consisting of more than one substance,
  with variable composition.

Is salt water a mixture?
16
Properties of Matter

• Intensive
• A quality of a pure substance which is
  independent of quantity
• color, melting point, hardness
• Extensive
• A quality of a pure substance which is dependent
  on quantity
• mass, volume

What are other intensive or extensive
properties?
17
Properties of Matter
Are taste and smell intensive or extensive
properties?
Is density an intensive or extensive property?
18
color density acidity phase mass flammability volu
me texture temperature boiling point modulus
of elasticity
Chemical Properties
Physical Properties
change of form not of substance
chemical reactions
19
Atomic TheoryJohn Dalton (1809)
In a chemical reaction, the way the atoms are
bound together changes, but the atoms dont
change.
20

• Let
• be oxygen
• Ó be carbon
• Ä be hydrogen
• be sodium
• ? be chlorine
• Rewrite the equation in terms of graphics

How does your chemical equation
demonstrate Daltons atomic theory?
21
Atomic TheoryJohn Dalton (1809)
In a chemical reaction, the way the atoms are
bound together changes, but the atoms dont
change.
22

• Each elemental substance cannot be divided
  indefinitely, but is composed of fundamental
  subunits called atoms.

• Atoms of different elements have different
  properties
• mass, size, reactivity, etc.

23

• In chemical reactions, atoms are never
  interconverted, created or destroyed.

Each pure compound contains different elements
which occur in a specific ratio with respect to
one another.
Chemical changes involve the rearrangement of
atoms.
24
Protons, Neutrons and Electrons
Fluorine atom
How many protons, neutrons and electrons are in a
fluorine-19 atom?
25
Protons, Neutrons and Electrons
Chloride ion
37
Cl
17
How many protons, neutrons and electrons are in a
chloride ion?
26
Protons, Neutrons and Electrons
Aluminum ion
27
Al3
13
How many protons, neutrons and electrons are in
an aluminum ion?