Reactivity of Metals

• Metals react with oxygen to form metal oxides
• Magnesium + oxygen = magnesium oxide
• If a metal gains oxygen, we say it has been oxidised. This is known as an oxidation reaction.
• Oxygen can be removed from metal oxides.
• The loss of oxygen is called reduction
• If a metal oxide reacts with hydrogen, it will form the metal and water
• Copper oxide + Hyrdogen = copper + water
• Reactivity series:

  Potassium

  Sodium

  Lithium

  Calcium

  Magnesium

  CARBON

  Zinc

  Iron

  HYDROGEN

  Copper

  Gold
• When metals react they have to lose electrons to form positive ions
• Some metals react with water and dilute acids
• Carbon and Hydrogen are included in the reactivity series as they can be used to extract some metals.
• We can test the reactivity of metals by placing them in water or dilute acids. The more bubbles produced, the more reactive the metal Is.
• Metals of the same mass and surface area are placed in the water or acid for the same amount of time to test how reactive they are.
• when magnesium, zinc and copper are placed in dilute acid, bubbles are produced.
• Heat's given out when metals react with the acid.

  The more reactive the metal, the greater the temperature change.
• A more reactive metal will replace a less reactive metal in a compound.

  This is known as a displacement reaction.
• Most metals are found as compounds and the pure metals have to be extracted
• Unreactive metals (such as gold) are found in a pure form in the Earth.

  However, most metals are found in compounds as metal oxides.
• Displacement reactions can be used to extract these metals from their oxides.
• If the metal is less reactive than carbon, carbon can be used to displace the metal from its oxide.
• Metals higher than carbon in the reactivity series have to be extracted by electrolysis .
• oxidation means the gain of oxygen.

  Oxidation also means the loss of electrons.
• reduction is the loss of oxygen.

  Reduction also means the gain of electrons.
• Oxidation Is Loss, Reduction Is Gain (of electrons).
• Oxidation and reduction can happen at the same time.

  Reactions where this happens are called redox reactions
• Displacement reactions are also redox reactions.