An
ion is a charged particle formed
when an atom (or molecule) loses or gains electrons. Atoms lose or gain electrons to attain a full
outer shell like the Noble Gases (Octet Rule).
When
atoms lose electrons, there are now more protons than electrons, so the ion has
a positive charge (ex. Na+)
When
atoms gain electrons, there are now more electrons than protons, so the ion has
a negative charge (ex. S2-)
Ionization Energy (IE)
The
first ionization energy of an
element is the minimum energy required to remove the most loosely bound
electron from an atom in the gas phase.
Homework
Analyzing First Ionization Energy - using
the data table and graph paper (or a plotting program):
- Plot
first ionization energy vs. atomic number for the first 38 elements. Be sure to include a title, labels and units. Join the points, one to the next, with straight lines. (/6)
-
You will find that you have 4 major high points (peaks) and 4 major low points (troughs). Label
peaks and troughs with element symbols. (/2)
-
Draw
Lewis diagrams for each peak and trough element. (/4)
-
What
is similar about all the peak elements? (/2)
-
What
is similar about all the trough elements? (/2)
-
Explain
the pattern of peak and trough elements. (/4)
