METALLIC BONDING

Metals conduct heat and electricity

Metals have theseproperties becauseof the way their atoms are joined together.

METALLIC BONDING

METALLIC BONDING

metal ion

mobile electrons

(de-localised)

Metals consist of ‘Giant structures’.The electrons from outer energy levels are free tomove through the whole structure . These electrons

* hold the atoms together ( + ions attract - electrons)

* allow the atoms to slide over each other (metals bend)* allow the metal to conduct heat and electricity

METALLIC BONDING

The atoms in a metal are closely packed so ……………………………………..

The atoms are in a regular pattern so ……………………………………..

Metallic bonding is strong so ……………………………………...

PHRASE LIST:

metals have high melting points metals are dense

they have a crystal structure

METALLIC BONDING

The atoms in a metal are closely packed so metals are dense.

The atoms are in a regular pattern so they have a crystal structure.

Metallic bonding is strong so metals have high melting points

PHRASE LIST:

metals have high melting points metals are dense

they have a crystal structure

METALLIC BONDING

The crystals on a metal’s surface are called grains.

Crystals join together atgrain boundaries

Galvanised dustbin

If cooled slowly larger crystals grow

giantelectrons outer positive

electrostatic

free

Cool liquid metal slowly to increase crystal sizeSmaller grains give a harder but more brittle metal

The de-localised electrons are like glue because:

they attract the positive metal ions (hold them together)

They are not like glue because: they are able to move through the whole lattice

METALLIC BONDING

http://www.chemguide.co.uk/atoms/structures/metals.html

The crystals on a metal’s surface are called grains.

Crystals join together atgrain boundaries

METALLIC BONDING

METALLIC BONDING

METALLIC BONDING

METALLIC BONDING

Copper ion

Zinc ionBrass

Small grains tend to stop rows of atoms sliding over each other.This makes the metal harder but more brittle.

METALLIC BONDING

Copper ion

Zinc ionBrass

METALLIC BONDING