Using resources. Flashcards
Humans rely on Earth’s resources for what?
to provide warmth, shelter, food and transport.
What do humans rely on now?
Agriculture to supplement or even replace such resources.
What are finite resources from the earth processed to provide?
Finite resources from the Earth, oceans and atmosphere are
processed to provide energy and materials.
What is potable water?
It is water that is good quality and is safe to drink.
How is potable water produced in the UK?
1)Fresh water from a source eg a lake or river is collected.
2) It is passed through a filter bed to remove solid particles
3) Chlorine gas is added to kill any harmful microorganisms.
4) Fluoride is added to drinking water to reduce tooth decay.
What can be used to sterilise water?
chlorine, ozone or ultraviolet light.
What are the 2 ways sea water can be desalinated to produce pure water?
Distillation and reverse osmosis. Both require lots of energy making it expensive.
What happens during distillation?
-The water is boiled to produce steam.
-The steam is condensed to produce pure liquid water.
What does sewage treatment include?
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- aerobic biological treatment of effluent.
Why is copper a useful metal?
-Good conductor of electricity/heat.
-Easily bent yet hard enough to make water pipes.
-Doesn’t react with water so it lasts a while.
Smelting.
-Copper can be extracted from copper-rich ores by heating ores with carbon in a furnace.
How can copper be obtained?
-From solutions of copper salts by electrolysis.
-By displacement using scrap iron.
Phytomining.
-uses plants to absorb metal compounds.
-The plants are harvested and then burned to produce ash that contains metal compounds.
Bioleaching-extracted from low grade-ores.
uses bacteria to produce leachate solutions that contain metal compounds.
The metal compounds can be processed to obtain the metal
When do metals corrode?
When they react with oxygen and water.
Rusting (When iron object corrode) equation
Iron + Water + oxygen = Hydrated iron (III) oxide.
How can corrosion be prevented?
By painting, electroplating or greasing a metal stopping oxygen and water from reaching the iron surface.
What happens in sacrificial protection?
A more reactive metal is placed in contact with the metal.
Eg blocks of magnesium are attached to the iron and they attract the ions.
Galvanising
-Object is coated in a layer of zinc.
The zinc layer stops oxygen and water from reaching the metal.
How is soda-lime glass made?
By heating a mixture of sand, sodium carbonate and limestone and is used as window glass.
How is Borosilicate glass made?
From sand and boron trioxide, melts at higher
temperatures than soda-lime glass.
How are clay ceramics made?
Made by shaping wet clay and then heating in a furnace.
What do composite materials consist off?
Consists of two materials with different properties. eg concrete.
Why are Life cycle assessments (LCAs) are carried out?
to assess the environmental impact of products in each of these stages:
* extracting and processing raw materials
* manufacturing and packaging
* use and operation during its lifetime
* disposal at the end of its useful life, including transport and distribution at each stage.
