Metals Flashcards
Is the melting point of transition metals low or high?
High
Do transition metals have a high or a low density?
High
True or false: Transition metals form coloured compounds
True
Transition metals can act as catalysts. What does this mean?
They can speed up chemical reactions without being used up themselves
What is corrosion?
Where metals become oxidised
What is rusting?
Corrosion of iron
Which conditions cause rusting to happen?
oxygen and water
How can rusting be prevented?
excluding oxygen, using a dessicant to remove water, painting, oiling or coating in plastic. Sacrificial protection
What is sacrificial protection?
Putting iron in contact with a more reactive metal to prevent iron rusting.
Why does sacrificial protection work?
the more reactive metal will oxidise more readily than iron, preventing iron from rusting
What is electroplating?
using electrolysis to put a thin layer of metal on the object.
How can electrolysis equipment be used to carry out electroplating?
The cathode is made of the object to be electroplated. The anode is made of the plating metal. The electrolyte contains ions of the plating metal
What is an alloy?
A mixture of two or more elements, where one element is a metal
Which is stronger, pure metals or alloys?
alloys
Why are alloys stronger than pure metals?
because when a metal is alloyed, the different elements have different sizes. This means the atoms do not easily slide over each other, making alloys stronger
