The Lewis dot structures for Ca3P2 and Al2O3 can be represented by indicating the ionic charges next to the symbols for the elements involved: Ca2+ for calcium, P3- for phosphorus, Al3+ for aluminum, and O2- for oxygen.
The Lewis dot structure for Ca3P2 and Al2O3 are representations of the bonding and valence electrons in these compounds. Since both are ionic compounds, their Lewis structures are simple. For Ca3P2, calcium (Ca) loses two electrons and becomes Ca2+, while phosphorus (P) gains three electrons for each P to satisfy its octet, forming P3-.
However, in Lewis structures, we typically do not illustrate the ionic bonds for such compounds. Instead, we acknowledge the ionic character by showing the charges on the ions.
For Al2O3, we have two aluminum ions with a +3 charge and three oxide ions with a -2 charge, resulting in a neutral compound. Each oxygen atom is surrounded by its six valence electrons in the form of lone pairs, and aluminum is represented simply as Al3+.