Name:___________________
Period:_________
Periodic Table
Ionic Bonds
PS-42
Big Question: Why do some atoms bond with other atoms?
Most elements want to give or take electrons from other atoms. But only electrons that are in an
unfilled shell can make the switch. So why do some atoms want more electrons, while others want less?
The answer is in the shell. Every atom wants its outer shell to be full of electrons. They hate unfilled
shells! How does an atom like Lithium fill its outer shell? Giving away the single electron in the second
shell makes the first shell its “outer” shell. On the other hand, chlorine has seven electrons in its outer
shell, but wants eight. So chlorine will accept the extra electron from lithium, which bonds them
together.
If I could only get rid
of this extra
electron…
If I could only find one more
electron…
Part 1: In the space below, draw atoms of sodium, chlorine, and oxygen.
Questions:
1. How many electrons are in the outer shell of sodium? _______________
2. How many electrons does chlorine need to fill its outer shell? ________________
3. How many sodium atoms can pair with one atom of chlorine? _____________
4. How many electrons does oxygen need to fill its outer shell? ________________
5. How many sodium atoms can pair with one oxygen atom? ___________
Name:___________________
Period:_________
Periodic Table
PS-42
Ionic Bonds
Part 2: Use your atom models from PS-41 to complete the tables below.
Donors
Number of extra
electrons in outer shell
Acceptors
Number of electrons
needed to fill outer shell
Li – metal
Oxygen – non metal
Na – metal
Fluorine – non metal
Be – metal
Chlorine – non metal
Mg – metal
Sulfur – non metal
H – nonmetal
___
Element
Number that can
pair with one atom
of chlorine
Number that can
pair with one
atom of oxygen
Lithium
1Li:1Cl (one lithium
for every chlorine)
2Li:1O (two
lithium for every
oxygen)
Magnesium
Beryllium
Sodium
Hydrogen
___
Number that can
pair with one
atom of Fluorine
Number that
can pair with
one atom of
Sulfur