Chapter 7 Ionic Covalent and Metal Materials

Types of Atoms Ionic Compounds: Covalent (Molecular Compounds): Metallic Solids: Ions (Ca+ions & Anions) Two or more nonmetal atoms 2 or more metals atoms

Electron Dot structures valence electrons: as dots around the atomic symbols EX. N e

Octet Rule - atoms react until contain 8 valence e- FNeNe _ (Fluorine) Ions achieve electron configuration as Noble Gas Neon

Halide Ions halogen, become negative gaining 1 electron. F I Br Fluorine Iodine Bromine _ _ _ Fl0urineFl0urine, Iodine and Bromine are all halogens - Halide Ions.

+ Ionic Bonds force binds oppositely charged ions Na Cl Sodium (Cation) Chlorine (Anion) - Sodium chloride Sodium

Electrostatic Attraction

B. Two types of compounds Ionic Compounds Made from IONS atoms w/ positive or negative charges. when an atom has lost or gained electrons. Good conductors when dissolved/melted. ca + ion & anion Electrically neutral Na + Cl - NaCl +Crystalline Solid -

Bond formation Ionic Compounds: Covalent (Molecular): Metallic Solids: Transfer of electrons Sharing of electrons Free moving valence e- Bond formation room temperature crystalline Hard & Brittle, High Melting pt solid, liquid or gas. soft & low melting point Soft to very hard Higher valence # of e-, harder metal. Electrostatic forces Very Strong Weak Strong

How many Na + surround Cl - ? Na+ Cl- Na+ Cl- Na+ Cl-

Compound Arrangement Ionic Compound Oppositely charged ions close packed layers. Unit cell repeating 3D pattern : Crystal

Even at this point, there was still a Polar Covalent Bond between Sara, Johnny and Bill… Johnny didn’t like the feeling of competing with Bill but he knew if he really wanted her, he’d have to fight for her. Stop in the name of Love, before You break my heart.

Covalent Compound nonmetals bonds between molecules are weak Water molecules Weak forces

Low to high mt. pts. Ductile: can be hammered into different shapes Malleable: can be drawn into wires Metals:

e-e- e-e- Form a bond Electron cloud

Conductors Metallic Solids: Good conductors of heat Why? Free-moving valence electrons Why?

in the molten state. or as electrolytes Ionic Compounds: Conductors Bonds break (melt) or dissociate (dissolve). Ions separate - free to move around. Poor conductors Molecular Compounds: Don’t form ions

Network Solids Consist of atoms held together by large network of covalent bonds. Each atom is covalently bonded in a large chain or network. There are NO molecules in a network solid, only atoms bonded together. Example: Diamond Bonds are very strong. Network Solid