KEY POINTS ABOUT METALLIC BONDING:
- Metals consist of a giant structure
- Metallic bonds involve 'free electrons'. These delocalised electrons come from the outer shell of every metal atom in the structure
- These electrons are free to move through the whole structure and so metals are good conductors of heat and electricity
- These electrons hold the atoms in a regular stucture
- There are stong forces of electrostatic attraction between the positive metal ions and the negative electrons
- They also allow the layers of atoms to slide over each other, allowing metals to be bent and shaped
REMEMBER: ALLOYS ARE HARDER THAN PURE METALS BECAUSE WHEN ANOTHER METAL IS MIXED WITH A PURE METAL, THE NEW METAL WILL DISTORT THE LAYERS OF METAL ATOMS, MAKING IT MORE DIFFICULT FOR THEM TO SLIDE OVER EACH OTHER. SO ALLOYS ARE HARDER!