Atoms and Bonding
Table of Contents
Atoms, Bonding, and the Periodic Table
Ionic Bonds
Covalent Bonds
Bonding in Metals
Atoms, Bonding, and the Periodic Table
Elemental Effects
The table lists some elements found in the compounds used in rockets.
It shows the effects these elements produce.
Atoms, Bonding, and the Periodic Table
Electron Dot Diagrams
The valence electrons of
an atom are shown as dots around the
symbol of the element. Complete the
electron dot diagram for neon.
Atoms, Bonding, and the Periodic Table
Periodic Table of the
Elements
The periodic table is
arranged in order of
increasing atomic
number. The number of
valence electrons also
increases from left to right
across a period. What is
the number of valence
electrons for each group?
Atoms, Bonding, and the Periodic Table
The symbols for the elements in Periods 2 and 3 are shown below.
Complete the electron dot diagrams for nitrogen, oxygen, fluorine,
sodium, magnesium, aluminum, silicon, and argon.
Atoms, Bonding, and the Periodic Table
Groups of Elements
Summary
• The number of valence electrons increases from left to right
across the periodic table
• Each period begins with an element that has 1 valence
electron and ends with an element that has 8 valence
electrons
• Elements within a group always have the same # of valence
electrons and therefore similar properties*
• The reactivity of metals decreases from left to right across the
periodic table
• Hydrogen shares e• Metals lose e• Metalloids lose or share an e• Non metals gain or share an e*hydrogen is the exception
Ionic Bonds
How Ions Form
An atom that
loses one of its
electrons
becomes a
positively charged
ion. The atom that
gains the electron
becomes a
negatively
charged ion.
Ionic Bonds
Ions
The table lists the names
of some common ions,
their charges, and their
symbols.
Ionic Bonds
Formation of an Ionic Bond
Follow the steps to see how an ionic bond forms between a sodium
atom and a chlorine atom. Complete the electron dot diagrams.
Ionic Bonds
A Maze
of Ions
What are three
pairs of oppositely
charged ions?
What would the
electron dot
diagrams be for
the ionic
compounds?
Ionic Bonds
Use the periodic table to complete the table.
Ionic Bonds
Halite
Ions in ionic compounds are arranged in three-dimensional shapes called
crystals. Some have a cubic shape.
Ionic Bonds
Galena
Galena, or lead sulfide (PbS), has a structure similar to that of table salt.
Covalent Bonds
Sharing Electrons
By sharing 2 electrons in
a covalent bond, each
fluorine atom gains a
stable set of 8 valence
electrons. Which are the
shared electrons that
form a covalent bond
between the
2 fluorine atoms?
Covalent Bonds
Covalent Bonds
Atoms can form single, double, and triple covalent bonds by sharing
one or more pairs of electrons.
How do Oxygen and Carbon Bond to form
Carbon Dioxide?
Covalent Bonds
Melting Points of Molecular and Ionic
Compounds
What information from the table helps to
make a bar graph of the melting points of
molecular and ionic compounds?
Covalent Bonds
Nonpolar and Polar Bonds
Hydrogen forms a nonpolar
bond with another hydrogen
atom. In hydrogen fluoride,
fluorine attracts electrons more
strongly than hydrogen does.
The bond formed is polar.
Covalent Bonds
Nonpolar and Polar Molecules
Both carbon dioxide and water molecules contain polar bonds. Where
would + and - signs be placed to show positive and negative charges?
Bonding in Metals
Metallic Bonding- Many of the properties of metals can be explained by
understanding the way they bond:
When metals bond with atoms of other elements they lose valence e- and
become positive ions because they do no hold onto their e- tightly.
The positively charged metal ions are embedded in a “sea” of valence electrons
which drift among them and they are free to move which allows metals to be:
conductive, lustrous malleable and ductile.
Covalent Bonds
Bonding Determines the Properties of a Substance
Complete the information, using water and sodium chloride as
examples.