Need help with basic chem questions? (1 Viewer)

[nkw]

Omg I feel really stupid But I'm having trouble understanding the whole positive/negative charge thing. For homework we were given a list of ions and we had to list the postive ion used, negative ion used, compound formula used, total positive charge and total negative charge.

I think I did okay up until the compound formula. I think I wrote the compound formulas right but now trying to figure out the positive and negative charges I'm wondering if I did do them right.'

The ions are:
(I'll put what I wrote for the compound formula in brackets next to each one)
-Sodium fluoride (NaF)
-Sodium oxide (Na2O)
-Sodium nitride (Na3N)
-Magnesium fluoride (MgF2)
-Magnesium oxide (MgO)
-Magnesium nitride (Mg3N2)
-Aluminium fluoride (AlF3)
-Aluminium oxide (Al2O3)
-Aluminium nitride (AlN)

Please help, I'm not sure if I did the formulas right and I'm also not sure how to work out the pos/neg charges from the compound formulas ???

 

[yeyjasminetime]

Omg I feel really stupid But I'm having trouble understanding the whole positive/negative charge thing. For homework we were given a list of ions and we had to list the postive ion used, negative ion used, compound formula used, total positive charge and total negative charge.

I think I did okay up until the compound formula. I think I wrote the compound formulas right but now trying to figure out the positive and negative charges I'm wondering if I did do them right.'

The ions are:
(I'll put what I wrote for the compound formula in brackets next to each one)
-Sodium fluoride (NaF)
-Sodium oxide (Na2O)
-Sodium nitride (Na3N)
-Magnesium fluoride (MgF2)
-Magnesium oxide (MgO)
-Magnesium nitride (Mg3N2)
-Aluminium fluoride (AlF3)
-Aluminium oxide (Al2O3)
-Aluminium nitride (AlN)

Please help, I'm not sure if I did the formulas right and I'm also not sure how to work out the pos/neg charges from the compound formulas ???

Hi nkw,

Positive ions = cations, Negative ions = anions

Take Sodium Flouride for example:

NaF - There is no subscript (x_y).
This means that the charges are equal and balance out. [the Na⁺ and the F^- balance out]

Na₂O - Oxygen is 2^- (look at where it is on the periodic table) and Sodium is 1⁺
Therefore, there needs to be 2 sodium cations for 1 oxygen anion.
Yeah?

It's important to look at the valence electron.

Good Luck