Transcript Chp5Sec1and2

Chapter 5 Atoms and Bonding
Table of Contents
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5.1 Atoms, Bonding, and the Periodic Table
5.2 Ionic Bonds
5.3 Covalent Bonds
5.4 Bonding in Metals
Chapter 5 Atoms and Bonding
Section 1:
Atoms, Bonding, and the
Periodic Table
How is the reactivity of elements
related to valence electrons in atoms?
Chapter 5 Atoms and Bonding
Section 1:
Atoms, Bonding,
and the Periodic Table
How is the reactivity of elements related to valence
electrons in atoms?
The number of valence electrons in an atom of an
element determines many properties of that element,
including the ways in which the atom can bond with other
atoms.
Chapter 5 Atoms and Bonding
Valence Electrons and Bonding
The number of valence electrons in an atom of an element
determines many properties of that element, including the
ways in which the atom can bond with other atoms.
Chapter 5 Atoms and Bonding
Section 1:
Atoms, Bonding, and the
Periodic Table
What does the periodic table tell you about the atoms of
elements?
Chapter 5 Atoms and Bonding
Section 1:
Atoms, Bonding, and the
Periodic Table
What does the periodic table tell you about the atoms of
elements?
The periodic table reveals the underlying atomic structure
of atoms, including the arrangement of the electrons.
Chapter 5 Atoms and Bonding
How the Periodic Table Works
The periodic table reveals the underlying atomic structure of
atoms, including the arrangement of the electrons.
Chapter 5 Atoms and Bonding
Electron Dot Diagram
An electron dot diagram includes the symbol for the element
surrounded by dot. Each dot stands for one valence
electron.
Chapter 5 Atoms and Bonding
Step 1: Write the symbol of the atom you are drawing the electron dot diagram for
in the middle of your paper. This symbol represents the nucleus of the atom and
each of the four sides represents an orbital.
Step 2: Locate the element you are drawing an electron dot diagram for on the
periodic table of elements. Find the number of electrons in one atom of the element.
The number of electrons is the same as the element's atomic number.
Step 3: Find the number of valence electrons by subtracting the number of
electrons in each level from the total number of electrons. There are two electrons in
the first level and eight in the second, third and fourth levels. The diagram will
represent only the outermost level of the electron field. Take the number of
electrons and subtract the number of electrons in each level until you come to a
level that is not entirely full. For the noble gases, the last level will be full, with no
electrons left over, and this is the level you will draw.
Step 4: Place the first two dots on the right side of the element symbol. This side is
referred to as the “s” orbital.
Step 5: Place the remaining dots in a counterclockwise fashion around the symbol.
Chapter 5 Atoms and Bonding
The Periodic Table
As the atomic number increases, the number of electrons
also increases. As a result, the properties of the elements
change in a regular way across a period.
Chapter 5 Atoms and Bonding
End of Section:
Atoms, Bonding, and
the Periodic Table
Chapter 5 Atoms and Bonding
Citations
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svg/198px-Atom.svg.png
•http://schoolhouse1.fenn.org/dduane/Science8th/bib_at1.jpg
•https://vinstan.wikispaces.com/file/view/P.gif
•http://images.google.com/imgres?imgurl=http://cdnwrite.demandstudios.com/upload//8000/900/50/2/48952.jpg&imgre
furl=http://www.ehow.com/how-does_4568765_electron-dotdiagramwork.html&usg=__mAeFs3IxkoVZDs188225ZlWtgeY=&h=1536&w
=2048&sz=291&hl=en&start=1&tbnid=PsP5jmiNNZGbUM:&tbnh=
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Chapter 5 Atoms and Bonding
Section 2:
Ionic Bonds
How do ions form bonds?
Chapter 5 Atoms and Bonding
Section 2:
Ionic Bonds
How do ions form bonds?
Ionic bonds form as a result of the attraction between positive
and negative ions.
Chapter 5 Atoms and Bonding
Ions and Ionic Bonds
You and a friend walk past a market that sells apples for 40
cents each and pears for 50 cents each. You have 45 cents
and want an apple. Your friend also has 45 cents but wants a
pear.
Chapter 5 Atoms and Bonding
What is an ion?
• When an atom gains or loses one or
more electrons, the charged particle
that results is called an ion.
• A known fact is that oppositely charged
particles are attracted to each other.
• This strong force of attraction is what
keeps the atoms stuck together as a
compound.
Chapter 5 Atoms and Bonding
Ions and Ionic Bonds
When an atom loses one of its electrons, it becomes a
positively charged ion. The atom that gains the electron
becomes a negatively charged ion.
Chapter 5 Atoms and Bonding
Ions and Ionic Bonds
Ions are atoms or groups of atoms that
have lost or gained electrons.
Polyatomic ions is a
group of atoms that
reacts as a unit.
Chapter 5 Atoms and Bonding
Section 2: Ionic Bonds
How are the formulas and names of ionic compounds
written?
Chapter 5 Atoms and Bonding
Section 2: Ionic Bonds
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How are the formulas and names of ionic compounds written?
When ionic compounds form, the ions come together in a a way
that balances out the charges on the ions.
Subscripts tells you the ratio of elements in the compound.
For an ionic compound, the name of the positive ion comes
first, followed by the name of the negative ion.
Chapter 5 Atoms and Bonding
Ions and Ionic Bonds
Ionic bonds form as a result of the attraction between
positive and negative ions.
Chapter 5 Atoms and Bonding
Section 2:
Ionic Bonds
What are the properties of ionic compounds?
Chapter 5 Atoms and Bonding
Properties of Ionic Compounds
•Hard
•brittle
•solids
•high melting points
•When dissolved in water,
they conduct electric current.
Chapter 5 Atoms and Bonding
Polyatomic Ions
Polyatomic Ions: - ions that are made of more than
one atom and reacts as a unit, having a positive or
negative charge. Also known as “radicals”.