Naming/Writing Binary Ionic Compounds
Honors Chemistry
Name
A binary ionic compound is composed of ions of two different
elements - one of which is a metal, and the other a nonmetal. For
example, sodium iodide, NaI, is composed of sodium ions, Na+
(elemental sodium is a metal), and iodide ions, I- (elemental iodine
is a nonmetal).
Rules: 1. The Cation (positive ion) is named first, the Anion second.
2. Monoatomic Cations take the element name
ex: Na+ --> Sodium Ca2+ --> Calcium
3. Monoatomic Anions take the elements name and ends with "-ide" ex: Cl- --> Chloride
NaCl --> Sodium Chloride
Li3N --> Lithium Nitride
Directions: Write the name of each binary ionic compound given below.
1. KBr
9. MgO
2. MgF2
10. Na2S
3. BeCl2
11. Sr3N2
4. LiF
12. CsCl
5. Ca3P2
13. ZnI2
6. BaS
14. AlP
7. Cs3N
15. Sr3As2
8. MgSe
16. Rb3P
Directions: Write the balanced chemical formula for each compound on the back of this page.
Rules: 1. Identify the symbols of the cation and anion ex. sodium sulfide–sodium is Na and sulfide is S
2. Identify the charge for each and place above the symbol; Na+ and S2Cations (Positive Ions)
All Group 1 elements in the Periodic Table are +1 in compounds.
All Group 2 elements in the Periodic Table are +2 in compounds.
Transition elements (have a few charges) will learn this later
Silver is 1+, Zinc is 2+ and Aluminum is 3+
Anions (Negative Ions): Group 17 are 1- Group 16 are 2- Group 15 are 33. Balance the positive and negative charges
Since each sodium is 1+ and each chloride is 2- then it will take two Na+ to balance one sulfide
with a 2- so that the charges when added together equal zero : 2(1+) + 1(2-) = 0. The numbers
outside the parenthesis become the subscripts in the formula.
Note, you may just crisscross the charges.
Na+ S24. Write the formula placing the subscripts right after the symbol they go with. Na2S
Directions: Write the balanced chemical formula for each compound.
1. barium chloride
2. beryllium nitride
3. potassium iodide
4. lithium fluoride
5. magnesium arsenide
6. sodium phosphide
7. aluminum sulfide
8. rubidium oxide
9. strontium oxide
10. cesium nitride
11. potassium phosphide
12. magnesium selenide
13. calcium bromide
14. Sodium chloride___________________