Metallic Bonding

Question 1

Metallic Bonding

Answer 1

Metal atoms achieve stability by “off-loading” electrons to attain the electronic configuration of the nearest noble gas. These electrons are delocalized and form a mobile sea of electrons, which prevents newly formed cations from flying apart due to the force of repulsion.

Question 2

Conductors

Answer 2

Because of the sea of delocalized electrons are mobile, valence electrons are free to move throughout the structure. Electrons attracted to the positive end are replaced by those entering from the negative end.

Mobile electron cloud allows for conductivity.

Question 3

Malleable and Ductile

Answer 3

Malleable - hammered into sheets

Ductile - can be drawn in rods and wires.

The bonding between the cations and mobile sea of delocalised electrons is non-directional. Individual metal atoms can move in relation to each other without breaking bonds between them and the sea of electrons.

Question 4

Solid at room temperature

Answer 4

Strong attractive forces between the metal ions and the sea of delocalised electrons hold the metal lattice together. As a result moderate to high temperatures are needed to disrupt the lattice and allow the metal to melt.

Question 5

Melting point - Electron density of the cloud

Answer 5

Melting point is a measure of how easy it is to separate individual particles.

Melting point increases across the period. The electron cloud density increases due to the greater number of electrons donated per atom. As a result ions are held more strictly.

Question 6

Melting point - Ionic/atomic size

Answer 6

Melting point decreases down the group. Ionic radius increases down the group. As the ions gets bigger the electron cloud becomes less effective holding them together so it becomes easier to separate.