1. Draw the Lewis dot structure for potassium bonded to chlorine. 2. Ionic bonds most commonly for between _______ and ___________. 3. A cation = ______________. Day metalsnonmetals a positive ion

1.Lewis dot structure for sodium = _____ How many times can it bond? 2.Lewis dot structure for sulfur = _____ How many times can it bond? 3.Lewis dot structure for the compound formed when sodium and sulfur bond to each other = ______

Electrostatic Force – an interaction between charged particles Opposites – Like charges – Attract Repel

3 main bond types: Ionic Polar covalent Nonpolar covalent

Cation – positive ion Anion – negative ion Ions – charged particles

Br Li BANG BrLi But they don’t separate … WHY? +- Electrostatic Force

Ionic bonds most commonly form between metals and nonmetals!

Ionic bonds are made up of charged pieces (ions) Ions can be made up of one element or a combination of elements (polyatomic ions)

Ionic Compounds: high melting points – strong bonds Brittle dissolve in water to produce mobile ions – good conductors

Electrostatic force Anion Ionic bond Malleable Alloy Cation

What are some properties that are unique to metals?

 Metals consist of closely packed closely packed cations and loosely held valence electrons rather than neutral atoms.  The valence electrons of atoms in a pure metal can be modeled as a sea of electrons.

The valence electrons are mobile and can drift freely from one part of the metal to another. Metallic bonds = the forces of attraction between the free-floating valence electrons and the positively charged metal ions.

Alloys = mixtures of two or more elements, at least one of which is a metal. Example = Brass is an alloy of copper and zinc. - Alloys are important because their properties are often superior to those of their component elements (steels).

Alloys Some of the most important alloys today are steels. The principal elements in most steels, in addition to iron and carbon, are boron, chromium, manganese, molybdenum, nickel, tungsten, and vanadium. Steels have a wide range of useful properties, such as corrosion resistance, ductility, hardness, and toughness. Stainless Steel 80.6% Fe 18.0% Cr 0.4% C 1.0% Ni

Key Concepts The valence electrons of atoms in a pure metal can be modeled as a sea of electrons. Alloys are important because their properties are often superior to those of their component elements.

Glossary Terms metallic bond: the force of attraction that holds metals together; it consists of the attraction of free-floating valence electrons for positively charged metal ions alloy: a mixture composed of two or more elements, at least one of which is a metal

Metals are made up of closely packed cations surrounded by a sea of electrons. The sea-of-electrons model explains why metals are good conductors and why they are ductile and malleable. Bonding and Interactions