Seperate chemistry 1 Flashcards
Where are the transition metals located on the periodic table?
In the middle.
What are the properties of the transition metals?
- High melting point
- High density
- Typical metal properties
Transition metals and their compounds make good what?
Catalysts.
What is a catalyst?
It speeds up the rate of reaction without being changed or used up itself.
The compounds of transition metals tend to be what?
Very colourful.
What are alloys?
They are made by adding another element to a metal - that could be metal or non-metal.
Why are alloys used rather than pure metals?
Pure metals have a regular arrangement of identical ions, the layers of ions can slide over each other. An alloy has different sized atoms making it more difficult for the layers to slide, so alloys are stronger.
Alloys of iron are called what?
Steels.
Why is iron alloyed with other metals to create steels?
It will rust fairly quickly on its own. Steel is also stronger.
What are aluminium alloys used for and why?
It is used for aircraft manufacture, as it has a low density.
What are gold alloys used for and why?
Jewellery- The purer the gold the higher the carat.
How is magnalium made and what is it used for?
Aluminium + Magnesium: Used to make parts of cars and aeroplanes. Magnalium with a higher magnesium content is used in fireworks.
Metals can corrode in the presence of what?
Oxygen and water to form metal oxides.
Oxidation of metals results in what?
Corrosion.
What is sacrificial protection?
This involves placing a more reactive metal with the iron. The water and oxygen react with this `sacrificial’ metal instead of the object you are protecting.
What is galvanising?
An example of sacrificial protection. A coat of zinc is put onto an iron object to prevent rusting.
What is electroplating?
This is when the surface of a metal is coated with another metal using electrolysis.
How do you electroplate an object?
The cathode is the object you’re going to electroplate the anode is the bar of metal you’re using for the plating. Your electrolyte is a solution containing the metal ions of the metal you’re plating.
How is electroplating useful?
- It stops metals reacting/corroding
- It improves the appearance of Jewellery and makes it look shiny