Year 8 Materials Flashcards
Where are the metals found on the periodic table?
In group 1, group 2 and the transition metals
What is the pattern of group 1 and 2 metals?
They get more reactive as they go down
Why do group 1 and 2 metals get more reactive as they go down?
The electrons in the outer shell are further away from the nucleus of the atom, so there is less attraction force, so they make bonds more easily
What gas is let off when group 1 metals react with water?
Hydrogen
What is the base equation for a metal reacting with an acid? Give an example
Metal + acid —> salt + hydrogen
Zinc + hydrochloric acid —> zinc chloride + hydrogen
What is thermal decomposition?
The breakdown of substances due to heat
What is neutralisation?
When an acid and a base react to form water and a salt
What is a physical change?
A change we can see happening, e.g. a change of state
What is a chemical change?
A rearrangement of atoms, where they change how they bond together
Is a chemical change reversible?
No
Is a physical change reversible?
Yes
What is an exothermic reaction? Give 2 examples
A reaction that gives out heat to its surroundings, e.g. combustion and respiration
What is an endothermic reaction? Give 2 examples
A reaction that takes in heat from its surroundings, e.g. thermal decomposition and photosynthesis
What is a catalyst?
A substance that changes the rate of reaction but is the same once the reaction is finished
How can using a catalyst reduce energy used?
Using a catalyst reduces the amount of energy needed to start a reaction
What is the chemical equation for burning?
Hydrocarbon + oxygen —> carbon dioxide + water (+energy)
What are the three essential ingredients for a fire?
Oxygen, heat and fuel
Where are the different parts of the periodic table found?
Group 1-2 - Alkali metals, group 3-6 - Transition metals, group 7 - Halogens, group 8/0 - Noble gases
What is a displacement reaction?
When a more reactive metal takes the place of a less reactive metal in a compound
What metals will produce a very high potential difference?
Metals far apart on the reactivity series
List the order of metals in the reactivity series
Potassium, Sodium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Tin, Lead, Copper, Silver, Gold, Platinum
How can you get pure iron from iron oxide?
Add carbon to it. Since carbon is more reactive than iron, it will displace it and you will end up with pure iron.
What is limestone used for in a blast furnace?
It combines with impurities in the iron oxide to form a liquid called slag
What is corrosion?
A natural process that turns a refined metal into its more stable form, usually reacting with oxygen to form a metal oxide
What metals corrode the easiest?
Metals high up on the reactivity series
What is rust?
A reddish or yellowish brown coating of iron oxide that forms on iron and steel
What conditions make rust occur more quickly?
Moisture, dilute hydrochloric acid and salt water
How can corrosion be prevented?
By protecting the metal surface with items such as paint or oil sealant
Why does aluminium not corrode?
It is covered by a natural layer of aluminium oxide, which prevents it from coming into contact with oxygen
What are composite materials?
Materials made from two or more materials with significantly different properties that produce a material with different characteristics.
What are ceramics?
Materials that are made of clay and put in a furnace
Give some properties of ceramics
Insulators of heat and electricity, brittle, stiff, can withstand high temperatures
What is a nanoparticle?
A particle with a size of 1-100 nanometres
