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Ions, Ionic Bonds and Metals

Chapter 7

Valence Electrons- Electrons in the outermost energy level of an atom

VE number = the Group Number of A elements

Ions and Ion Formation

Electron Dot Structures (Diagrams) show the valence electrons ONLY drawn around the symbol of the element.

Electrons only pair after there is an electron on each side of the symbol

Lewis Structures

Remember- Metals give away and Nonmetals take VE

All elements want 8 VE

Bonds occur because of the giving/taking of electrons which result in charges

Opposite Charges attract

Bonding

Octet Rule- all elements want to have 8 valence electrons and will bond to achieve this

Noble Gases- Group 8A= 8 VE Don’t bond because they have already

achieve the Octet Rule

Octet- Rule of 8

Metals- lose VE and gain a positive charge based on number of VE lost

Cations

Nonmetals/Metalloids- Gain VE and gain a negative charge based on number of VE gained

Anions

Meeting the Octet Rule

Cations: Name: Metal Name “Ion” Lithium Ion

Anions: Name: Root Name, end in –ide Chlorine (Cl-) becomes “Chloride” “Halide”- halogen ions

Naming Ions

Electrical Charges of Ionic Compounds is ALWAYS “0” or neutral.

Cations (+) and Anions (-) have opposite forces

Opposites attract and are held together

The electrostatic forces that hold ions together in ionic compounds are called ionic bonds

Ionic Compounds

Chemical Formula- shows the numbers of atoms of each element in the smallest representative unit of a substance.

Formula Units- the lowest whole-number ratio of ions in an ionic compound.

Chemical Formula & Formula Units

1.) Crystalline Solid at room temperature Very Stable Structure due to large

attractive forces

2.) High Melting Points- lots of energy to change state of matter

3.)Conduct Electricity when dissolved in water

Properties of Ionic Compounds

When Melted or in Dissolved in Water:

Ions dissociate and exist in a solution + and – charges floating that conduct

electricity

Conducting Electricity

Valence Electrons are mobile and drift freely from one part of the metal to another

Metallic bonds are the forces of attraction between the free-floating valence electrons and the positively charged metal ions.

Metallic Bonding

Ductile- can be drawn into wires

Malleable- can be hammered into thin sheets without breaking

High Melting Point- requires a lot of energy to break the bonds

Metal Properties

Crystalline Structure- compact, orderly, repeating pattern

Metals form crystals in 3 forms: Every atom except those on the surface

have: Body Centered- 8 neighbors Face Centered- 12 neighbors Hexagonal Close-Packed- 12 neighbors

(hexagonal shape)

Metallic Structures

Mixtures of 2 or more elements; at least 1 is a metal

Ex. Brass

Properties are superior to the elements that make it- STRONGER

Stainless Steel

Alloys

Page 214; # 27-51 Write the electron dot structures for:

Li, Mg, Al, N, O, F, Cl, Ne

Identify all possible IONIC bonds

Assignment