1. Ionic Formulas Turning chemistry into algebra

2. REVIEW We can tell how many electrons an atom will gain or lose by looking at its valence electrons. Metals like to lose electrons. (Cations) – Ex. Na + Nonmetals like to gain electrons. (Anions) – Ex: O 2- All elements try to have a full valence of 8 electrons(OCTET RULE).

3. REVIEW Cation- is a positively charged ion. How do cations form? – When atoms LOSE electrons they become positive. Anion- is a negatively charged ion. How do anions form? – When atoms GAIN electrons they become negative.

4. Chemical Bonding A chemical bond is the force of attraction that holds two atoms together. Attractive Force NaCl

5. Why do elements form chemical bonds? Atoms form chemical bonds in order to fill their outermost energy level with electrons. A full valence causes an atom to be more stable. A full valence consists of 8 valence electrons.

6. Ionic Bonding Ionic bonds: Metal atoms transfer electrons to nonmetal atoms. Producing oppositely charged ions (cation & anion) which attract each other. Na + + Cl -  NaCl

7. Write an ionic formula for Na + bonding with F − Balance the charges. Na + F − (1+) + (1-) = 0 1 Na + and 1 F − = NaF

8. Write an ionic formula for K + bonding with S 2− Balance the charges. K + S 2− K + 2(1+) + (2-) = 0 2 K + and 1 S 2− = K 2 S

9. Write an ionic formula for Fe 3+ bonding with OH − Balance the charges. Fe 3+ OH − OH − (3+) + 3(1-) = 0 1 Fe 3+ and 3 OH − = Fe(OH) 3

10. Write the formula for… an ionic compound composed of: Al 3+ and S 2- Al 2 S 3

11. Write the formula for… an ionic compound composed of: Fe 2+ and SO 4 2- FeSO 4

12. Write the formula for… an ionic compound composed of: Cd 2+ and NO 2 - Cd(NO 2 ) 2

13. Write the formula for… an ionic compound composed of: Ag + and CO 3 2- Ag 2 CO 3

14. Write the formula for… an ionic compound composed of: Pb 2+ and NO 3 - Pb(NO 3 ) 2

15. Write the formula for… an ionic compound composed of: Hg 2+ and PO 4 3- Hg 3 (PO 4 ) 2