Question

1. Find the elements magnesium, cesium, and nitrogen on the periodic table. a. What monoatomic ions would each form? Write this with the appropriate symbol abbreviation. Be sure to use subscripts or superscripts as necessary. Example: Al3+ (5 points) b. Then, given what you know about chemical bonding, give the formulas for the types of ionic compounds they would produce with each other. Be sure to use subscripts or superscripts as necessary. Explain how you determined this. No credit without an explanation. (10 points)

Answer 1

a. Monatomic ions

Cs is in Group 1. It has one valence electron that it can lose to form a Cs⁺ ion.

Mg is in Group 2. It has two valence electrons that it can lose to form an Mg²⁺ ion.

N is in Group 15. It can gain three valence electrons to complete its octet and form an N³⁻ ion.

b. Ionic compounds

In an ionic compound there must be the same number of positive and negative charges.

It takes three Na⁺ ions to balance the charge on one N³⁻ ion, so the formula of sodium nitride is Na₃N.

It takes three Mg²⁺ ions (charge = +6) to balance the charge on two N³⁻ ions

(charge = -6), so the formula of magnesium nitride is Mg₃N₂.