NAME_______________________________________________ PERIOD ____
BINARY COMPOUNDS : FORMULA WRITING
1. look up the elements represented in the name and find their oxidation numbers (charges)
2. How Many? Multiply by the number of pieces (atoms) that will make the total + and _ charges match.
3. The number you multiplied by in step #2 IS the subscript for the formula SEE EXAMPLES
Elements
Final formula
Ions & Oxidation # HOW TO SHOW WORK
Ex 1. potassium bromide
K+1
Br -1
K1Br1 OR KBr
+1 x 1=+1
-1 x 1 = -1
+1
Ex 2. sodium phosphide
Na3P1 OR
Na3P
Na
P-3
+1 x 3 = +3
1. lithium fluoride
2. beryllium bromide
3. potassium iodide
4. magnesium sulfide
5. calcium nitride
6. hydrogen selenide
7. potassium oxide
8. aluminum bromide
9. zinc phosphide
10. silver oxide
11. gallium chloride
12. barium nitride
13. strontium fluoride
14. beryllium sulfide
15. calcium nitride
16. magnesium phosphide
17. potassium iodide
18. sodium oxide
19. zinc chloride
20. lithium phosphide
-3 x 1 = -3