CHEM 121 Chapter 3

3-minute review Draw the Lewis Structures for each of the following neutral atoms: Cs Na F Ar

Reactivity of Elements Compounds form so each atom can have a Ionic compound: Covalent compound:

Ions: charged particles Metals Nonmetals + -

3-minute review Predict whether these bonds in these molecules are ionic or covalent Br2 CaO MgCl2 NO2

Ionic Charge Elements Elements ordered by atomic number “Periodic” trends Periodic table by Mendeleev (1871)

3-minute review Predict the most common ion for each of these: O I S Mg Cs Al N

Electron Configurations For ions: Ex. O2- Ex. Al3+

Common ions in the body

Ionic Compounds Cation + Anion + Strontium and Iodine Nitrogen and Cesium

3-minute review Write the name for the compound that forms between the following pairs of elements: Sodium and fluorine Bromine and calcium Sodium and sulfur Sulfur and magnesium

Ionic Compounds

Ionic Compounds Net ionic charge Examples: Potassium chloride Calcium bromide Magnesium sulfide Lithium oxide

3-minute review Write the formula for the following compounds: Sodium bromide Magnesium chloride Potassium sulfide

Metals that form more than one ion Usually in B groups (transition metals) Ex. Iron chromium copper gold iron lead tin Cr2+ Cu+ Au+ Fe2+ Pb2+ Sn2+ Cr3+ Cu2+ Au3+ Fe3+ Pb4+ Sn4+

3-minute review Write the name for AuN Write the formula for the following compounds: Copper (II) iodide Chromium (III) sulfide Lead (IV) oxide

Properties of Ionic Compounds + -

Polyatomic Ions Monatomic Ions: Cl- Na+ Polyatomic ions: Examples: See Table 3.5 in your book

Polyatomic Ions Nitrate: charge = Sulfate: charge = Examples:

3-minute review Name the following: Al(OH)3 NaNO3 KNO2 MgSO4