Metals

- The periodic table is split into 2 groups – metals & non-metals - Examples of metals: aluminium (Al)

iron (Fe) copper (Cu)

zinc (Zn) silver (Ag)

gold (Au)

- Examples of non-metals: hydrogen (H) carbon (C)

nitrogen (N) oxygen (O)

sulfur (S)

Uses - Batteries (Li) - Jewellery (Ag, Au, Pt) - Street lights (Na) - Fertilisers (K)

Properties - Shiny, lustrous appearance - Malleable – can be hammered into different shapes - Ductile – can be stretched into thin wires

- High melting & boiling points - Good conductors of heat & electricity - Can corrode – react with oxygen to form oxides

Alloys - An alloy is a mixture of metals - Examples: bronze = copper & tin (statues)

brass = copper & zinc (instruments)

steel = iron & carbon (construction)

Solder = tin & lead (electrical circuits) - Alloys are harder & less likely to corrode than the metals they are made from

Rusting - When a metal like iron (Fe) reacts with oxygen on the presence of water it forms iron oxide (rust) Fe + O FeO - The rusting of iron is a chemical process that changes it into a new substance, iron oxide

- Oxygen & water are necessary for rusting to occur - Corrosion by rusting is preventable: - painting - greasing/oiling - galvanising (coating a metal with zinc) - chromium plating (coating a metal with chromium)

Group I – Alkali metals - They are in the same group so have the same properties: - easily cut with a knife - shiny when cut - less dense than water

- 1 electron in outer shell - reactivity increases down the group - stored under oil to prevent them reacting with oxygen & water in the air Alkali metals

- Alkali metals react with oxygen to form white oxides: lithium + oxygen lithium oxide sodium + oxygen sodium oxide potassium + oxygen potassium oxide

- Alkali metals react with water to form a metal hydroxide & hydrogen gas: lithium + water lithium hydroxide + hydrogen gas sodium + water sodium hydroxide + hydrogen gas potassium + water potassium hydroxide + hydrogen gas - The hydroxide dissolves in the water to form an alkaline solution that turns litmus blue

- All metals react with an acid to form a salt & hydrogen gas metal + acid salt + hydrogen gas Zn + 2HCl ZnCl2 + H2 zinc + hydrochloric zinc + hydrogen acid chloride gas

Activity series - Some metals are more reactive than others, e.g., calcium, magnesium, zinc & copper - The activity series is a list of metals in order of decreasing reactivity: K, Na, Ca, Mg, Al, Zn, Fe, Pb, Cu, Hg, Ag, Au most reactive least reactive