Topic 7 - Metals

Positively charged metal ions touching in regular lattice Delocalised elections floating between

The electrons that a metal has lost to become an ion. They just float around

The electrostatic attraction between the positive metal ions and the delocalised electrons

Because to conduct you need • charged particles • that are free to move The delocalised electrons fit both of these criteria

When force is applied to metals, the top layer of ions slide across the one underneath it, causing it to bend

A mixture of a base metal and alloying agents

1) swapping out some of the base metal atoms and replacing them with alloying agent atoms 2) jamming some alloying agent atoms between some of the base metal atoms

The alloying agent atoms in an alloy tend to be a different size to those of the base metals atoms, distorting the layers of metal atoms and so the layers slide less easily.

K Na Li Ca Mg Al C Zn Fe Pb H Cu Ag

Potassium -> calcium: very reactive Magnesium -> zinc: fairly reactive Iron to silver -> not very reactive Gold: not at all reactive

There is only enough energy for one of the bonds to be broken Metal + cold water -> metal hydroxide + hydrogen Magnesium, zinc and iron won’t react much Copper won’t react

There is enough energy to break both bonds Element + steam -> element oxide + hydrogen Copper won’t react

Place the metal into a beaker of water and hold a burning splint close to the metal to test the gas given off

Group 1

1) place some mineral wool soaked in water at the base of a test tube held horizontally 2) place a strip of metal half-way up the test tube 3) plug the test tube using a bung with a hole through the centre where u place a small plastic cylinder 4) beat the mineral wool and metal with Bunsen burners 5) the steam will react with the metal, producing hydrogen gas 6) test the hydrogen gas with a burning splint

• they have low melting and boiling points • they are very soft and can be cut easily with a knife • they have low densities • they react quickly with water, producing hydroxides and hydrogen gas • their hydroxides and oxides dissolve in water to form alkaline solutions

Li (s) + H2O (l) -> LiOH (aq) + 0.5H2 (g) • fizzing • solid disappears • moves on surface of water

Na (s) + H2O (l) -> NAOH (aq) + 0.5H2 (g) • faster • fizzing • solid disappears • moves on the surface of the water

K (s) + H20 (l) -> KOH (aq) + 0.5H2 (g) • fizzing • solid disappears • moves on surface of water • lilac flame

They get more reactive as the group descends, because as the group descends, the outermost electron is further away from the nucleus, meaning it’s attraction is weaker, and it is more easily lost. This can be seen through their reactions with water and oxygen

They thermally decompose

heat metal carbonate ——> metal oxide + CO2

When a metal and a dissolved compound react, they displace each other (but only if the metal is more reactive)

1) what is happening to the elements 2) what is happening to the compounds