Naming Compounds & Formulas (December 9, 2024)

December 9, 2024 Monday Naming Compounds Writing Formulas  Systematic Naming IUPAC  There are too many compounds to remember the names of them all.  Compound is made of two or more elements.  Put together atoms.  Name should tell us how many and what type of atoms. ...

December 9, 2024 Monday Naming Compounds Writing Formulas  Systematic Naming IUPAC  There are too many compounds to remember the names of them all.  Compound is made of two or more elements.  Put together atoms.  Name should tell us how many and what type of atoms.  Periodic Table  More than a list of elements.  Put in columns because of similar properties.  Each column is called a group. 1A Representative elements 0 2A 5A 7A 3A4A 6A  The group A elements Metals  Metals  Luster – shiny.  Ductile – drawn into wires.  Malleable – hammered into sheets.  Conductors of heat and electricity.  Transition metals  The Group B elements  Dull Non-metals  Brittle  Nonconductors - insulators Metalloids or Semimetals  Properties of both  Semiconductors  Atoms and ions  Atoms are electrically neutral.  Same number of protons and electrons.  Ions are atoms, or groups of atoms, with a charge.  Different numbers of protons and electrons.  Only electrons can move.  Gain or lose electrons.  Anion  A negative ion.  Has gained electrons.  Non metals can gain electrons.  Charge is written as a super script on the right. -1 Has gained one electron F -2 Has gained two electrons O  Cations  Positive ions.  Formed by losing electrons.  More protons than electrons.  Metals form cations. +1 Has lost one electron K +2 Has lost two electrons Ca  Compounds  Follow the Law of Definite Proportion.  Have a constant composition.  Have to add the same number of atoms every time.  Two types.  Two Types of Compounds  Molecular compounds  Made of molecules.  Made by joining nonmetal atoms together into molecules.  Two Types of Compounds  Ionic Compounds  Made of cations and anions.  Metals and nonmetals.  The electrons lost by the cation are gained by the anion.  The cation and anions surround each other.  Smallest piece is a FORMULA UNIT.  Two Types of Compounds Ionic Molecular Smallest Compound Molecule piece Types of Metal and Nonmetals elements Nonmetal Solid, liquid State solid or gas Melting High >300ºC Low