Writing Formulas and Naming Compounds When compounds form, the net charge always equals zero. The number of + always equals the number of

Lets picture what happens Na + + Cl - are attracted to each other. Na + and O 2- are attracted to each other. Na + Cl - O 2- Na + NaCl Na 2 O

Your turn: Use the following ions to make as many compounds as you can. You may use your ion sheet. potassium magnesium Gallium Lithium chloride oxide hydroxide phosphide phosphate Cl 1- O 2- (OH) 1- P 3- PO 4 3- Li 3 PGaPMg 3 P 2 K3PK3PP 3- Ga(OH) 3 Mg(OH) 2 KOH(OH) 1- Li 2 OGa 2 O 3 O 2- KClCl 1- Li 1+ Ga 3+ Mg 2+ K+K+ MgCl 2 GaCl 3 LiCl K 2 OMgO LiOH

K+Mg 2+ Ga 3+ Li + Cl - O 2- OH - P 3- Potassium chloride Potassium oxide Potassium hydroxide Potassium phosphide Magnesium chloride Magnesium oxide Magnesium hydroxide Magnesium phosphide gallium phosphide

Oxidation number The charge on a monatomic ion is called the oxidation number. An ion with more than one atom, has a different oxidation number on each atom, so the sum of the oxidation numbers equals the charge of the ion. Your ion sheet lists some common oxidation numbers for metals.

Reading Isotopes S Mass number Charge or oxidation number atomic number = number of protons

Reading Isotopes F Mass number Charge or oxidation number atomic number = number of protons

What is the oxidation numbers of sulfur in this compound? CaSO of 2- = -8 ? 0 = ? ? = 6

What is the oxidation numbers of phosphorous in this compound? Na 3 PO 4 3 sets of 1+ 4 of 2- = -8 ? 0 = ? ? = 5

Write the formula for the following compounds: –calcium chloride –sodium cyanide –magnesium oxide Ca Cl 2 NaCN Mg MAKE SURE THE CHARGES ARE BALANCED! O

Write the formula for the following compounds: –silver and fluorine –nickel (II) and sulfur –chromium (III) and bromine Ag F NiS Cr MAKE SURE THE CHARGES ARE BALANCED! Br 3

4. Write formulas for the following. barium sulfate barium sulfide magnesium phosphate strontium bromide chromium (III) acetate Ba 2+ SO 4 2- S 2- Mg 2+ PO 4 3- Sr 2+ Br 1- Cr 3+ C 2 H 3 O 2 1- BaSO 4 BaS Mg 3 (PO 4 ) 2 …….

mass number = number of protons + number of neutrons atomic number = number of protons # neutrons = mass # - atomic # # electrons = # protons Explain lead-207’s parts Pb mass number atomic number

Naming Binary inorganic compounds. Al 2 S 3 Aluminum Al 3+ Sulfide S 2- K3PK3P Potassium K + Phosphide P 3- The charges not needed for naming most compounds The charges are only needed for writing chemical formulas.

Naming Binary inorganic compounds containing transition metals. Cr 2 S 3 chromium (III) Cr 3+ Sulfide S 2- Cu 3 P copper (I) Cu + Phosphide P 3- The charges ARE needed for naming these compounds The charges are also needed for writing chemical formulas.

To name covalent compounds Covalent compounds are composed of two or more nonmetals which share electrons. (Some metalloids are covalently bonded as well). USE PREFIXES mono = 1 penta = 5 di = 2 hexa = 6 tri = 3 hepta = 7 tetra = 4 octa = 8

prefix if not mono-name of less electronegative atom, prefix of second atom– ending ide Naming covalent compounds CO 2 CO P 2 O 5 mono = 1 penta = 5 di = 2 hexa = 6 tri = 3 hepta = 7 tetra = 4 octa = 8 carbon di ox ide carbon mon ox ide di phosphorous pent ox ide Try SF 6 sulfur hexafluoride

Naming Organic Compounds Organic compounds have one or more carbons, surrounded with hydrogens. They may have double or triple bonds, and may include oxygen, or other atoms. They are named by counting the “carbon backbone” and applying a prefix “Functional Groups” provide the rest of the name. meth = 1 eth = 2 prop = 3 but = 4 pent = 5 hex = 6 hept = 7 oct = 8 non = 9 …

Naming Organic Compounds Butane = 4 carbons CH 3 CH 2 CH 2 CH 3 Heptane = 7 carbons CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 CH 3 Octane = 8 carbons CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 3 meth = 1 eth = 2 prop = 3 but = 4 pent = 5 hex = 6 hept = 7 oct = 8 non = 9 …