Metallic Bonding

Science 10

Metallic BondingOccurs between metalsForm giant structures where electrons

are free to moveThe bond is the force of attraction

between metal ions and free electrons

Fixed cations in a sea of electrons

Properties of Metals

Can you think of some?

Properties of Metals

Can you think of some?

– Silver, shiny, soft– Reactive, form cations by losing electrons– Poor insulators– Good conductors

Properties of Metallic Bonds

Bonds are strong– Maintain regular structure (solids)– High melting and boiling points

Good conductors of electricity and heat– Sea of free electrons carries heat through the

metal

Properties of Metallic Bonds

Ductile and malleable– Free electrons allow metal atoms to slide over

each other– Ductile - drawn out– Malleable- hammered into sheets

Metallic Animation

http://www.youtube.com/watch?v=ijw8OBt4btM

Classwork

Create a table comparing ionic, covalent and metallic bonding

Venn diagram of 3 types of bonds

Other Molecular Forces

When we say something is polar we mean that it has two opposite ends.

The earth is polar. It has a north and a south pole.

These poles have magnetic properties.

And this affects the way the earth interacts with other forces in the universe.

Hydrogen BondingAtoms can also be polar.

Because the nucleus of an oxygen atom is so much bigger then the nucleus of a hydrogen atom, the electrons in a water molecule move slightly towards oxygen.

Because the oxygen has more electrons around it that atom will have a slightly negative charge.

The hydrogen atoms are left with a slightly positive charge.

This polarity causes water molecules to be attracted to one another.

Demo: drops of water on a coin, water bridge.

Hydrogen Bonding

An element that contains polar hydrogen atoms, can attract other polar molecules.

Van der Waals (London Dispersion)

Electrons are always floating around an atom randomly.

Sometimes, the electrons will end up closer to one side of the atom.

This will make the atom polar for a moment.

Homework:Study for quiz: naming and making

ionic, polyatomic and molecular compounds.