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71 Cards in this Set
- Front
- Back
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What makes up an atom?
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Inside an atom, there is a nucleus and electrons. The nucleus is made up of protons and neutrons, which is in the middle of the atom.
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What are the electrical charges of protons, electron, and neutrons?
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Protons have a positively charged
Electrons have a negative charged Neutrons don't have a charge as it is neutral |
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Why don't any atom have an electric charge?
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Atoms do not have an electrical charge because the number of protons balances the number of electrons.
So when a proton is taken from an atom, its charge would be negative as there are more electrons and vice versa. |
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What does the mass number and atomic number tell you in the periodic table? |
The mass number is the total number of protons and neutron The atomic number is the number of electrons, which the same number of protons. |
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What maximum number of electron found in the first shell and the second shell.
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The first shells can only hold two electrons whereas any more than two shells can hold up to eight electrons
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What is a compound?
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It is when different element reacts together to form a chemical bond, which is usually difficult to separate the originals element out again
It can consist of giving, taking and sharing an electron. |
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What is ionic bonding?
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It occurs when a metal and non-metal reacts together. Which the metal loses its electron and gives it to the non-metal, by doing this the non-metal will have gained an electron.
As a result, the non-metal will have a negative charge compared to the metal having a positive charge. |
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What is covalent bonding?
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It occurs when two non-metals consists of molecules. The atom then shares an electron with another atom.
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How to balance this equation?
H2SO4 + NaOH → Na2SO4+ H2O |
H2SO4 + 2NaOH → 2Na2SO4+ H2O |
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What is limestone normally made of? |
Limestone is mainly made of calcium carbonate, CaCO3 |
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What would happen when limestone is thermally decomposed?
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When limestone is thermally decomposed it would change into calcium oxide and carbon dioxide.
Calcium carbonate → calcium oxide + carbon dioxide |
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What would happen when limestone reacts with an acid?
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When reacting it with an acid it would produce a calcium salt, carbon dioxide, and water.
eg. Calcium carbonate + sulfuric acid → calcium sulfate + carbon dioxide + water |
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What would happen when calcium oxide reacts with water?
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When water is added to calcium oxide would produce calcium hydroxide.
Calcium oxide + water → calcium hydroxide Calcium hydroxide is an alkali and can be used to neutralise acid rain |
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How to make calcium hydroxide from calcium hydrogen? |
To make calcium oxide from calcium hydroxide is to add carbon dioxide. Calcium hydrogen + carbon dioxide → calcium hydroxide + water |
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What are the building materials that can be made from limestone?
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Limestone can be made into...
- Cement (heated with powdered clay) - Mortar (cement mixed with sand and water) - Concrete (cement mixed with sand and aggregate) |
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What are the Pros of quarrying limestone?
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Pros
- Provides jobs for people and bring money to the economy, while providing what people want - Limestone used in power station chimneys to neutralise sulfur dioxide and can neutralise acidic soil - Once quarrying is completed, landscaping and restoration are often required |
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What are the Cons of quarrying limestone?
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Cons - It makes large ugly holes which can make permanently change the landscape - Destroys habitats of animals - Blasting rocks apart with explosive makes lots of noise and dust in quiet area - Limestone is transported away by lorries cause noise and pollution |
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What is an ore?
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It is a rock that contains enough metal to make it worthwhile extracting the metal from it. In most ores there is an oxide of the metal, which needs to be extracted from the metal using a chemical reaction.
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How are metals extracted by reduction using carbon (chemically)? |
Only the metals that are less reactive than carbon that is extracted by reduction, those that are more reactive are used for electrolysis.
When ore (ie. iron oxide) is added to blast furnaces, carbon is added to react with oxygen and allow the iron to melt. Iron oxide + carbon → iron + carbon oxide |
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How are metals extracted by electrolysis?
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Metals that are more reactive than carbon is extracted by electrolysis of molten compounds.
The method consists of having a high temperature to melt down an ore (eg. aluminium oxide) so that the metal can be extracted, this requires lots of energy and is quite expensive. |
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How is copper purified by using electrolysis?
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In the anode, there is an amount of impure copper, while at the cathode there is a thin piece of pure copper. There should also be a solution of copper(II) sulfate containing Cu2+ ions.
Electrons are pulled off copper atoms at the anode, causing them to go into the solution as Cu2+ ions. Cu2+ ions near the cathode gain electrons and turn back into copper atoms. As the pure copper atoms bond in the cathode, the impurities are dropped at the anode as a sludge. |
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How can you extract metal from a solution using a displacement reaction?
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If you put a reactive metal into a solution of dissolved metal compound, the reactive metal will replace metal in the compound. This because the more reactive metal bonds more strongly to the non-metal bit of the compound and pushes out the less reactive metal.
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How to extract copper by using bioleaching?
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This uses bacteria to separate copper from copper sulfide. The bacteria gets energy from the bond between copper and sulfate, separating the copper from the ore in the process. |
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How to extract copper by using phytomining?
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This uses plants to be grown in soil containing copper. As the plant can't get rid of the copper, it will start to build up in the leaves. These plant can then be harvested, dried and burned in a furnace. The copper can be collected from the ash left in the furnace.
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What are the Cons and Pros of metal extraction?
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Pros
- It allows useful product to be made - Provide jobs to local people and bring money in the area, which can mean that service such as transport and health can be improved Cons - Bad for the environment as it cause loss of habitats and scarring of landscape - Deep mines can be dangerous for a long time after the mine has been abandoned |
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Why is it important to recycle metals?
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- Mining and extracting metals take lots of energy, most of which comes from burning fossil fuel
- Fossil fuel is running out and burning them contributes to acid rain, global dimming, and climate change - There is only a finite amount of metals on Earth - Recycling metal cuts down on the amount of rubbish that gets sent to landfill, which takes up space and pollutes surroundings |
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What are properties of metal?
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- They are strong and hard to break
- Great at conducting heat - Great at conducting electricity - Can be bent |
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What is an alloy?
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It is a mixture of two different type of metal
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What are metals that we use today that is often made from an alloy?
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Alloys are harder than pure metal
Bronze = copper + tin - good for making statues and metals Gold alloy is used in jewelry - pure gold is too soft Aluminum alloy is used in aircraft - Aluminum has a low density, with the alloy it makes it stronger |
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What does crude oil consists of?
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It is a mixture consists of two (or more) elements or compounds that aren't chemically bonded to each other, most of which are hydrocarbon molecules.
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How is Crude oil split into separate groups of hydrocarbon?
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A fractionating column works continuously, with heated crude oil piped at the bottom. The vapourised oil rises up the column and the various fractions are constantly tapped off at the different levels of condensation.
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What is a formula for an alkane?
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CnH2n+2
CH4 = Methane C2H6 = Ethane C3H8 = Propane C4H10 = Butane |
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What is an alkane?
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It is made up of chains of carbon atoms surrounded by hydrogen atoms, which has chains of different lengths. As all of the atoms have formed bonds with as many other atoms as they can, this means that they're saturated.
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Is a short-chain hydrocarbon more viscous and volatile than a long chain hydrocarbon?
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A shorter molecule of hydrocarbon have a more liquid property and less viscous, they are also more volatile as it turns into a gas at a low temperature. Due to this, it would have a lower temperature to vaporises or condense and have a low boiling point. On top of this the shorter the molecules, the more flammable it becomes
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Why is crude oil important?
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It is important because it burns cleanly to make good fuel, which is used in cars, boats, trains and planes. They are also used in the central heating system in homes and power stations to generate electricity. There is also a large industry with scientists working on finding oil reserves. On top of this, it is readily available as there is filling station around the country for vehicles it is the cheapest and easiest to use
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What does crude oil do to nature?
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- Oil spills can happen as oil is transported by tanker, which is a disaster for the local environment. As when animals are covered they poisoned and birds can no longer fly
- It must be burnt to collect energy from it, leading to global warming, acid rain and global dimming |
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How to reduce acid rain?
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It can be reduced by reducing the sulfur dioxide emissions, which can be done by...
- Be removed from fuels before they're burnt - Replace petrol and diesel for low-sulfur versions - Reduce usage of fossil fuel - Have Acid Gas Scrubbers to take the harmful gases out before releasing fumes into the atmosphere |
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What is the theory of global dimming?
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It is believed that when particles of ashes and soot are produced when fossil fuels are burnt. These particles reflect sunlight back into space or produce more clouds to reflect sunlight back into space.
However, many scientists believe this change is real and blames it on inaccurate recording equipment |
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What is the alternative fuel that can be used? (NOT petrol and diesel)
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Ethanol- Produced from plant material so it is a biofuel. It is made by the fermentation of plant and can be mixed with petrol
Biodiesel- Produced from vegetable oil, eg. rapeseed and soybean oil. Can be mixed with diesel Hydrogen gas- Using hydrogen from electrolysis of water |
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What is cracking?
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It is a when long-chain of hydrocarbon is split up into smaller hydrocarbons, by breaking the bonds.
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What sort of reaction is cracking and what does it do?
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It is a thermal decomposition reaction, which breaks down the molecule by heating them.
To begin, the large hydrocarbon has to be heated to help vapourise it (turn it into gas). This vapour is then passed through a powdered catalyst at the temperature of 400 to 700 C, the catalyst is often aluminium oxide. The long-chain molecules then split apart or "crack" on the surface of the specks of the catalysis |
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What is the general formula of alkene and what is an alkane?
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The general formula is CnH2n
C2H4= Ethene C3H6= Propene Alkene is hydrocarbons which a double bond between two of the carbon atoms in their chain. They are unsaturated as they can make more bond as the double bonds can open up, allowing the two carbon atoms to bond with other atoms. |
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How to tell whether a solution is an alkene?
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By adding bromine water to the solution. This is because if the solution was an alkene the bromine water would turn from orange-brown to colourless as the double bonds have been opened.
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What does ethane make when it reacts with steam to produce?
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Ethane can be hydrated with steam in the presence of a catalyst to make ethanol. This can be a cheap method as not much is wasted, however, ethane is produced from crude oil which means that it is a non-renewable resource which can run out quite soon which can make it expensive in the future.
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How can ethanol be produced using renewable energy?
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It can be done by fermentation, where sugar is converted to ethanol into yeast Sugar → carbon dioxide + ethanolThis has a lower temperature and simpler equipment than using ethane. |
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What are the Cons and Pros of using renewable ethanol?
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Pros
- It can be used by less developed countries as it can be mixed with diesel as fuel - It is a renewable source Cons - It isn't very concentrated, so to increase the strength it needs to be distilled which in turn need to be purified |
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How to make polymers using alkene?
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It is done by polymerisation, this means joining up lots of small molecules (monomers) to more a very large molecule, this long chain of molecules is called a polymer.
eg. When many ethanes join together it would produce ploy(ethane), just as many propenes molecules would produce ploy(propenes). |
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What would affect the physical properties of polymers?
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- What type of alkene it is made from
- The temperature and pressure of polymerisation as those made in high-temperature and high-pressure lead to the polymer being more flexible and has low density. But polymers made from low-temperature and low-pressure with a catalyst is dense and rigid |
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What is the usage of polymers?
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- light, stretchable polymers that have low density is used to make plastic bags
- Waterproof coating for fabrics is made of polymers. Dental polymers are used in rental tooth filling. Polymer hydrogel wound dressing keeps it moist. - Mattresses made of memory foam is a polymer that gets softer as it gets warmer. |
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What are the problems with polymers?
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- Most polymers aren't "biodegradable" so that they cannot be broken down by microorganisms, so they don't rot.
- It is difficult to get rid of them, as when they are placed in landfill they will still be there for many years to come -Although they are cheaper than metal, it is made from crude oil can get used up so that the price may rise |
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How is oil be extracted from plants?
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To get the oil out, the plant material is crushed. The next step is to press the crushed plant material between metal plant to squeeze the oil out
Another method is to crush the plant material by using a centrifuge, similar to a spin-dryer to get water out Distillation can be used to refines oil, and remove water, solvents and impurities |
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What are the benefits of using vegetable oil for cooking?
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- Vegetable oil has a higher melting point than water, this means that they can be used to cook food at a higher temperature and at a faster speed
-Cooking food in oil gives food a different flavour, as the oil carries the flavour - Using oil to cook food increases the energy we get from getting it |
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How is vegetable oil good for producing fuel?
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Vegetable oil has a lot of energy that can be released, which makes it suitable to be used for fuel. This is called biodiesel, where it has similar properties to ordinary diesel fuel.
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What type carbon-carbon bond does an unsaturated oil contains?
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The unsaturated oil contains C=C double bonds, which are between some of the carbon atoms in their carbon chains.
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What happens when unsaturated oil becomes hydrogenated?
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Unsaturated oil is a liquid at room temperature. However, it can be hardened when it's reacted with hydrogen with a nickel catalysis at 60C. This is called hydrogenated. What happens is that the hydrogen reacts with the double bonds, causing it to be saturated.
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What is hydrogenated oil?
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It is saturated oil with no double bonds, due to this they have a higher melting point which means that it is a solid at room temperature. It is the results of unsaturated oil becoming hydrogenated.
Those that are partially hydrogenated are often used instead of butter in processed foods, like biscuits. These oils are cheaper and can be stored longer. However, this can be bad for you. |
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What are the Cons and Pros of oil (saturated and unsaturated) to your health?
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Vegetable oil is normally unsaturated while animal fat tends to be saturated Pros- Unsaturated oil reduces the amount of blood cholesterol Cons - Partially hydrogenated vegetable oil and saturated fat can increase the amount of cholesterol in the blood and can increase the risk of heart diseases |
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How is emulsion made from oil and water?
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As oil don't dissolve in water, when it is mixed together it will create an emulsion that is made up of lots of droplets of liquid suspended in another liquid. This is an oil-in-water emulsion or a water-in-oil emulsion.
Emulsions are thicker than either oil or water, eg. mayonnaise is an emulsion of olive oil and vinegar, as it is thicker than either |
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What keeps oil and water mixed?
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Emulsifiers are molecules with one part that's attached to water (hydrophilic) and another that is attached to oil (hydrophobic). Because of this, it is why the emulsion won't separate out
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What are the Cons and Pros of emulsifiers?
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Pros
- Emulsifiers stop emulations from separating out and give a longer shelf-life - Allow companies to reduce fat in foods while still having good texture Cons - Some people are allergic to certain emulsifiers, so it is important to check ingredient more carefully |
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How did Wegener work on his theory of continental drift?
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When Wegener was comparing a listing the fossils of similar animals and plant found in South America and Africa. He believes that there was once a land bridge linking the continent so that animals were able to walk across, but has sunk or been covered over since then. He then notices that the coastline of two continent had matched like two pieces of a jigsaw, There were also matching layers of rocks in the two continent.
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What was Wegener's theory of continental drift?
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Wegner believes that about 300 million years ago there was a supercontinent called Pangaea, which over time had broken up into smaller checks which moved apart. Claiming that these chunks of our modern day continent are still slowly "drifting" apart.
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Why wasn't Wegener's theory accepted for many years?
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- Wagener has used inaccurate data in his calculation and wild predictions on how fast the continent was moving
- Wagner studies astronomy and wasn't a geologist, so only a few scientists supported him - Wegner thought that continents were "ploughing through" seabed and that their movement was caused by tidal forces and the earth rotation. |
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What is inside the Earth?
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- On the surface, there is the crust which is very thin (5-50 km) and is surrounded by the atmosphere
- Below that there is the mantle. It has all of the properties of a solid, except that its move very slowly. Within the mantle, radioactive decay takes place. Producing a lot of heat, causing the mantle to flow in a convection current. - At the centre of the Earth, there is the core, believed to be made of iron and nickel |
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What are tectonic plates?
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They are cracks in the crust and the upper part of the mantle, which are in a large number of places. They are like big rafts "floating" on the mantle. However, they do not stay in one place as convection current in the mantle causes them to drift. This can result in an earthquake or volcanoes.
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Why can't scientists accurately predict earthquakes and volcanic eruptions?
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Scientists may find clues that an earthquake might happen, like the strain in underground rocks. However, it is likely that these clues will tell whether an earthquake is likely to happen, rather than where it is going to happen.
Before an eruption, molten rock rises up to the chambers near the surface, causing a mini earthquake. But sometimes molten rock cools down instead of erupting, so mini-earthquakes can be a false alarm |
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How and why is today's atmosphere completely different from Earth early atmosphere, 200 million years ago? |
200 million years ago the Earth's astosphere was filled most of CO2, with almost no oxygen. There were also a small amount of methane and ammonia, with some amount of water vapour. Similar to Mars and Venus today. Oceans then form due to the water vapour. Green plants and algae evolved all over the Earth in CO2 atmosphere, which over-time dissolved in oceans of water and had been absorbed by green plants and algae. |
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What is meant by primordial soup theory?
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It states that billions of years ago, the Earth atmosphere was rich in ammonia, nitrogen, hydrogen and methane. When lightning struck, it had caused a chemical reaction between the the gases resulting in amino acid being created. The amino acid collected in a "primordial soup", where a body of water of life eventually crawled out from. The idea was that amino acids gradually combined to produce organic matter which eventually evolved into simple organism. |
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Why do we fractionally distill air?
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We functionally distill air to get a variety of products (eg. nitrogen and oxygen) to be used in industry. |
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How do we fractionally distill air
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This is done by... - Air is filtered to remove dust - It's then cooled to around -200 C and becomes a liquid - During cooling water vapour condenses and removed, CO2 freezes and is also removed. - The liquefied air then enters the fractional column and is heated slowly - The remaining gases are the separated by fractional distillation. Oxygen and argon come out together so another is used to separate them |
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How does burning fossil fuels affect the oceans and the climates?
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- There will be an increase of carbon dioxide which may cause global warming, which means that there would be climate change - The oceans is a natural storage of carbon dioxide, which is absorbed from the atmosphere. However, the extra carbon dioxide makes it too acidic. Which is bad for corals and shellfish, as a result, it means that they won't be absorbing any more carbon dioxide |
