#1) Draw the following ions using a Bohr diagram:

b)oxygen: i got [oxygen:2)8)]-2 (the -2 is an exponent) but the answer said [oxygen: 2)8)8)]-2...is this right?
d)fluorine: i got [fluorine:2)8)]-1 and the book says [fluorine: 2)8)8)]-1..again, is the book making a mistake?

#8)Using Lewis structures, draw the formation of the following ionic bond and write its chemical formula: magnesium and phosphorus, magnesium and nitrogen

Your book is wrong on both counts. You are correct.

Thanks Bob, that makes it very frustrating for me b/c all night I was thinking that I was doing it wrong!

could you please help me with this question as well:

#8)Using Lewis structures, draw the formation of the following ionic bond and write its chemical formula: a)magnesium and phosphorus b) magnesium and nitrogen

For question #1, you are correct that oxygen has an electron configuration of 2-8. However, the correct Bohr diagram would include 8 electrons in the outermost energy level, not just 2. So the correct Bohr diagram for oxygen would be [oxygen: 2)8)8)]^-2.

Similarly, for fluorine, you are correct that its electron configuration is 2-8. However, again, the outermost energy level can accommodate up to 8 electrons, so the correct Bohr diagram for fluorine would be [fluorine: 2)8)8)]^-1.

For question #8, let's first determine the electron configurations of magnesium and phosphorus and magnesium and nitrogen.

Magnesium (Mg) has an atomic number of 12. Its electron configuration is 2-8-2.

Phosphorus (P) has an atomic number of 15. Its electron configuration is 2-8-5.

Nitrogen (N) has an atomic number of 7. Its electron configuration is 2-5.

To form an ionic bond, magnesium will give away its 2 valence electrons to either phosphorus or nitrogen to achieve a stable octet configuration. Let's see the formation of the ionic bond between magnesium and phosphorus:

Magnesium (Mg): [Mg: 2)8)2)]

Phosphorus (P): [P: 2)8)5)]

Since magnesium loses 2 electrons and phosphorus gains 3 electrons, the chemical formula for the ionic compound formed will be Mg3P2.

Similarly, the formation of the ionic bond between magnesium and nitrogen would be:

Magnesium (Mg): [Mg: 2)8)2)]

Nitrogen (N): [N: 2)5)]

Since magnesium loses 2 electrons and nitrogen gains 3 electrons, the chemical formula for the ionic compound formed will be Mg3N2.