metals

• Alloys - alloys are types of metals which are made by combining a metal with another element.
• In alloys, however, the particles are different sizes. This means that the layers can no longer slide over each other as easily.
• Some metals burn vigorously in air. The metal reacts with the oxygen in the air to produce a metal oxide.
• magnesium + oxygen -> magnesium oxide
• power of oxygen = -2
• group 1 metals power = +1
• group 2 metal power = +2
• group 3 metal power = +3
• calcium + oxygen -> calcium oxide/ Ca2O2
• The most reactive metals are on the left side of the periodic table. The less reactive ones are on the right.
• Metals appear to get heavier when they react with oxygen, this is because the oxygen atoms are getting added onto the metal.
• Not all metals react with water. Some metals, however, react vigorously with water, producing bubbles of hydrogen gas and an alkaline solution.
• Corrosion - is the reaction of metals with substances from the environment. Many metals corrode.
• Rusting - A type of corrosion is rusting, which is the corrosion of iron
• rust = hydrated iron (|||) oxide
• iron + oxygen + water -> hydrated iron(|||) oxide
• An iron nail will rust in water as oxygen and water are both present.
• An iron nail will rust in salty water. You don't need salt for rusting but it makes the object rust faster.
• Iron will not rust in boiled water with a layer of oil on the top because, only water is present out of oxygen and water. But for rusting you need both
• Iron will not rust with calcium chloride. This is because only oxygen is present, but you need both oxygen and water for there to be a reaction/rusting.
• Physical barriers such as paint, grease or plastic coating prevent rusting as they do not allow water or oxygen to reach the metal. If the barrier is broken or damaged, rusting will occur. Electroplating coats the metal in a metal which doesn't rust e.g. silver or gold. Sacrificial protection uses a metal which is more reactive. This metal reacts in preference. Galvanising is when iron is coated with zinc. The zinc reacts instead of the iron.
• Some metals react with acid. The general equation for this reaction is : metal + acid -> salt + hydrogen
• When the acid used is hydrochloric acid, chloride salts are formed: magnesium + hydrochloric acid -> magnesium chloride + hydrogen
• most reactive metal to least reactive (including gases): potassium, sodium, calcium, magnesium, aluminium, carbon, zinc, iron, nickel, tin, lead, hydrogen, copper, mercury, silver, gold and platinum.
• Gold remains chemically unchanged for thousands of years.
• Unreactive metals such as gold are found in the earth. As the metal itself, but most metals are found as ores that require chemical reactions to extract the metal.
• The reactivity series is a list of metals from most to least reactive. Carbon is a gas and is found under aluminium and before zinc in the reactivity series.
• A displacement reaction involves a metal higher than carbon in the series. So no reaction will take place to extract it you can use electrolysis.
• A displacement reaction happens when a more reactive metal displaces a less reactive metal.