Transition metals, alloys and corrosion.

• What is a transition metal?

  The type of metals that sit in the middle of the periodic table.
• Transition metals are good conductors, have high density.
• Transition metals can form many colored compounds, such as copper sulphate, which is blue.
• Transition metals can be used as good conductors like iron used in the Haber process.
• The oxidation of metals result in corrosion.
• What is corrosion?

  The gradual destruction of materials by chemical or electrochemical reactions with their environment.
• What are the 3 ways of preventing iron from rusting?

  1. Placing a barrier between the iron and water/oxygen
  2. Painting or oiling your objects
  3. Sacrificial protection (Galvanisation) coating a metal with a more reactive metal so that it reacts with oxygen instead.
• What is Electroplating?

  The process of coating a thin layer of metal onto another metal using Electrolysis.
• Electroplating can be used to improve the appearance and/or the resistance to corrosion of metal objects.
• What is an alloy?

  A mixture of two or more metals.
• Pure metals can be easily shaped and bent because it has a regular arrangement of identical atoms. The layers of ions can slide over each other.
• Alloys can make metals stronger and harder than pure metals. This is because they have different-sized atoms. The different-sized atom from a different element disrupts the layers of the pure metal - making it more difficult for the layers to slide against each other.
• Why is iron alloyed with other metals to produce different types of steel?

  Steel is harder than iron, iron can rust on its own and enhance its overall properties.
• Carbon makes steel hard but brittle. If there's too much carbon then the steel will break when stretched. To prevent this, small amounts of other elements are added to the steel.
• Bronze = Copper + Tin. It is used to decorate elements.
• Brass = copper + zinc. Used for creating instruments and door fillings.
• Gold is soft and brittle on its own. Metals such as zinc and copper are used to harden the alloy. 75% = 18 karat gold.
• Aluminium alloys are used to make aircraft because of its low weight and density.
• Magnalium = aluminium + magnesium. Used in fireworks as it corrodes less than pure magnesium.