

Check your answers and then answer the rest
of the questions based on this video.
Intro to Ionic/Covalent Video

What is the “goal” of atoms? What makes them
happy?


To achieve a filled valence shell.
How can atoms achieve this?

To do this, atoms must gain or lose electrons to form ions.
Or others share electrons. ( both are forms of bonding)
They make an Ion• Atom that has gained or lost an electron,
and therefore has a positive or negative
charge based on the number of electrons
it has lost.
Cation- positively charged ion
 Anion- negatively charge ion




What is an Ionic
Bond?
Complete transfer
of 1 or more
electrons from one
atom to another
(one loses, the
other gains)
forming oppositely
charged ions that
attract one another
Good Animation on
Ionic Bonding


What is a
Covalent Bond
Some valence
electrons are
shared between
atoms to achieve
a “full” valence
shell.
A bond can result from an overlap of atomic orbitals
on neighboring atoms (sharing of electrons in
those orbitals).
••
H
+
Cl
••
•
•
H
••
Cl
•
•
••
Overlap of H (1s) and Cl (3p)
Note that each atom has a single, unpaired
electron.


Remember that
valence electrons are
the electrons in the
OUTERMOST energy
level.
We know this by
looking at the groups
on the Periodic Table.

2 Methods:



Draw up the Lewis Dot Structures.
Swap Charges (works only for ionic)
How to Make Ionic Bonds

Step 1, determine the # of valence
electrons (either through group #
for first 18 or through looking at
electron configuration)
If you can lose them, then you get a +
charge. Why?
 If you need them, you get a (-) charge.
Why?


Step 2, Then write the Atomic
Symbol, surrounded by the
electrons represented as dots.

Step 3, place the dot structures next to each
other (metal first if ionic bond). Then exchange
dots.


Write each of the atoms with their charges.
Then swap the charges down to the front of the
other atom to determine how many you need
of each to balance out the charges.


Subscripts determine the number of atoms of
that element in the molecule.
Coefficients determine how many molecules
you have.