1. Explain (step-by-step) how to form ionic bonds between Li+ and N-3. First, understand that all atoms want full shells. All atoms, except for noble gases, have valence electrons. These electrons are the ones on the outermost shell. All atoms either want to get rid of these electrons or gain enough to make a full shell. Metals, which are on the right side of the periodic table, have less than 4 valence electrons. This means they want to get rid of those electrons. Nonmetals, which are on the left side of the periodic table, have more than 4 valence electrons. These atoms want to gain electrons until they have 8, which is a full shell. Metals will always be positive because they are giving AWAY electrons, so therefore, they have more protons (+) than electrons (-). Nonmetals will always be negative because they will GAIN electrons, so therefore, they will have more electrons (-) than protons (+). So to form an ionic bond between lithium (metal) and nitrogen (nonmetal), you first look at how many lithium valence electrons there are. You can determine this by looking at lithium’s charge which is +. + means that there is only one. For nitrogen, you look at the group that nitrogen is. Nitrogen is in Group 15, so it has 5 valence electrons. So how many of each atom can make the entire compound neutral? You need THREE lithium atoms so that they each give away one valence electron to nitrogen. This way, all the atoms are happy because they all have full shells.
Shortcuts:
-For the number of valence electrons for the metals, look at the charge. + means 1 valence electron, +2 means 2 valence electrons, +3 means 3 valence electrons and so on.
-For the number of valence electrons for the nonmetals, add their charge to 8. For example, nitrogen is
-3. Adding -3 to 8 would equal 5, which is the number of valence electrons for nitrogen.
-To find the number of atoms for each atom, look on the opposite charge. For example, the problem above.