CHAPTER 12 THE EARTHS RESOURCES Flashcards
What is a synthetic resource
A substance made by chemical reactions to imitate a natural resource
What is phytomining
Using plants to extract copper
What is bioleaching
Using bacteria to extract copper
What are finite resources
A resource that will eventually run out
What are renewable resources
A resource that can be replaced at the same rate it’s being used
What is sustainability
Developments that meet the needs of current generations without compromising the ability of future generations to meet their own needs
3 examples of finite resources
Metal ores
Crude oil
Limestone
What is potable water and how is it different from pure water
Water that has been processed and is safe for human consumption and daily use. And pure water is solely made up of H2O compounds whereas potable water may contain different substances usually dissolved salts and minerals
3 characteristics of potable water
-Ph between 6.5 and 8.5
-The dissolved substances will be present but in very regulated quantities
-Be free of bacteria or potentially harmful microbes
What is fresh,surface and ground water
Fresh water - water whats relatively free from dissolved substances (rainwater)
Surface water - a body of water that is exposed at the surface (lakes or oceans)
Ground water - in aquifers which are porous rocks which store water underground
Method of purifying and testing water samples (6) RP
1)= measure the ph of the water using the universal indicator
2)=weigh a clean,dry watch glass
3)= then place 5cm^3 of water in the watch glass and gently heat it over a beaker of boiling water to evaporate the water and leave any dissolved on the watch glass. Then weigh the watch glass to find the mass of any dissolved solids.
4)=steam from the boiling sea water passes through the delivery tube and condense to liquid water in the cooled test tube. Any dissolved solids present remain in the conical flask
5)=a portion of of distillate from 4 is tested for ph
6=a portion of distillate from step 4 is tested for the presence of dissolved solids
What is desalination
It involves the treatment of seawater to remove the salt by distillation or reverse osmosis
What happens in reverse osmosis
Salt water is forced through a semi-permeable membrane at high pressure which allows only water to pass through it but prevents any other dissolved chemicals passing through it
What is the problem with desalination(3)
-It’ very expensive
-consumes large amounts of energy
-produces greenhouse gases
Steps of treating waste water(4)
1.screening - removes large materials like twigs or grit
2.sedimentation - occurs in sedimentation tank where water stands still while heavier solids sink to bottom which creates sewage sludge, whilst light materials known as effluent floats to the top
3.- air is pumped into water to encourage the breaking down of organic matter and other microbes by aerobic bacteria
4.anaerobic digestion - is used to break down the sewage sludge from the bottom. it’s removed and placed into large tanks where bacteria breaks it down.
What are 2 products from the anaerobic phase of treating waste water
-fertiliser from the leftover digested waste
-methane gas produced as by product from the organic matter in the sludge and can be used as a source of energy
What are order of magnitude calculations and how to do them
Used when the exact number isn’t crucial instead a estimate is sufficient.
Calculation values are rounded to the closest power of 10.
