Chapter 2: Molecules, Ions, and Compounds MACROSCOPIC SCALE Elements combine to make compounds. ATOMIC SCALE Atoms combine to make molecules, or extended structures.
What we’ll cover… Compound Formulas Ions Ionic Compounds Monatomic Polyatomic Ionic Compounds Molecular Compounds Other types of extended Structures
Compound Formulas Examples: NaCl CH3OH (NH4)2SO4
Three Types of Compounds Molecular Covalent Extended Covalent Ionic
Types of Formulas
IONS Cations Formed by losing electrons. Have a positive charge. Formed mainly from metals.
IONS Cations Formed by losing electrons. Have a positive charge. Formed mainly from metals. Anions Formed by gaining electrons. Have a negative charge. Formed mainly from nonmetals.
Monatomic Ions- Formed from single atoms
Naming IONS Cations Name of element + “ion” Na+ = sodium ion Mg2+ = magnesium ion
Naming IONS Cations Name of element + “ion” Na+ = sodium ion Mg2+ = magnesium ion Anions Name of element with –ide ending + “ion” Cl- = chloride ion O2- = oxide ion
Polyatomic Ions you need to know
Ionic Compound Formulas Total cation charge = Total anion charge Ex: Na+ and Cl- make ________
Ionic Compound Formulas Total cation charge = Total anion charge Ex: Na+ and Cl- make NaCl Mg2+ and Cl- make ________
Ionic Compound Formulas Total cation charge = Total anion charge Ex: Na+ and Cl- make NaCl Mg2+ and Cl- make MgCl2 NH4+ and SO42- make _________
Naming Ionic Compounds Name = cation name + anion name Ex: NaCl = NH4Br =
Molecular Compounds Nonmetal + nonmetal gives molecular compound Ex: C + O S + O C + H
Aside on gas prices… Propane Butane Jet Fuel Gasoline Diesel/Heating Longer molecules(asphalt/tar) Crude oil
Predicting Molecular Compound Formulas
Naming Molecular Compounds Binary Compounds form between 2 elements
Naming Molecular Compounds Binary Compounds form with 2 elements Element with highest group # named last, like it’s an anion.
Naming Molecular Compounds Binary Compounds form with 2 elements Element with highest group # named last, like it’s an anion. Use prefixes to indicate numbers: 2 = di 3 = tri 4 = tetra 5 = penta
Network Solids Held together like a molecule Large and extended