+ What’s in a name?

+ LOL ASAP FYI BRB

+ What are chemical formulas? What can a chemical formula tell us? Number of atoms of a particular element present in a chemical compound Ex. CO 2, NO 2 For ionic compounds, the ratio between the positive and negative ions within the chemical compound Ex. NaCl, MgCl 2 Monoatomic ions— Ions originating from ONE atom Cation—named by element Anion—named by element, drop ending and add –ide ending Ex. O -2, N -3, Mg +2

+ C 6 H 12 O 6

+ Binary Compounds—Writing Chemical formulas 1) Cation, Anion. (write element names) 2) Write oxidation number/charge on each element. 3) Balance charges by the smallest common multiplier between the two elements. Charges must add to 0 for a neutral compound. 4) Add the subscripts for each element in the chemical compound.

+ Example 1: Sodium chloride “salt”

+ Example 2: Aluminum oxide

+ You try….. 1) Magnesium bromide 2) Lithium chloride

+ 5) If the first element is a transition element, the oxidation number or charge of the element is given by a Roman numeral (I, II, III, IV, etc.) following the element name. Exceptions: Ag +1 and Zn +2 —they will always have these charges.

+ Example 3: Tin (IV) sulfide

+ Example 4: Iron (III) oxide

+ You Try….. 1) Zinc oxide 2) Mercury (II) fluoride

+ Try….. 1) Calcium chloride 2) Copper (I) oxide 3) Sodium bromide 4) Potassium sulfide 5) Calcium oxide

+ Binary Homework—write chemical formula with chemical name. 1) Iron (II) oxide 2) Potassium bromide 3) Magnesium chloride 4) Chromium (III) oxide 5) Calcium fluoride 6) Iron (III) sulfide 7) Manganese (IV) sulfide 8) Strontium sulfide 9) Zinc bromide10) Copper (II) oxide