Friday, 20 March 2015

Science homework

Please post advice for the school here explaining how rusting occurs, how it can be prevented and why it is irreversible.

15 comments:

  1. Rusting occurs by a chemical reaction, it is caused by a mix of moisture, iron or steel and oxygen. Water and oxygen are all both needed to make rust occur. To prevent rusting you could coat it in many things. Like:
    - Oil based paint
    - Oil
    - Petroleum jelly
    - Varnish

    Personally, the petroleum jelly and the varnish can last the longest.

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  2. Iron and steel rust when they come into contact with water and oxygen. Both water and oxygen are needed for rusting to occur. Rusting can be prevented through covering in plastic coating, paint, galvanising, or bringing into contact with magnesium. When iron is exposed to the atmosphere it reacts with the oxygen and forms iron oxide. The iron cannot then be recovered.

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  3. RUST

    Iron and steel rust when they come into contact with water and oxygen. They rust faster in salty water or acid rain. Aluminium, on the other hand, does not corrode easily, because its surface is protected by a layer of aluminium oxide.


    PREVENTION

    Stainless steel is an iron alloy that does not rust. It is used to make kitchen sinks, for example.

    There are several ways to prevent iron and steel rusting. Some of these work because they stop oxygen or water reaching the surface of the metal:

    oiling - for example bicycle chains

    greasing - for example nut and bolts

    painting - for example car body panels

    Iron and steel objects may also be covered with a layer of metal. Food cans, for example, are plated with a thin layer of tin.

    Empty cans of food
    ‘Tin’ cans are made of steel coated with a thin layer of tin metal

    Galvanising
    Galvanising is a method of rust prevention. The iron or steel object is coated in a thin layer of zinc. This stops oxygen and water reaching the metal underneath - but the zinc also acts as a sacrificial metal. Zinc is more reactive than iron, so it oxidises in preference to the iron object.

    Sacrificial protection – Higher tier
    The reactivity series lists metals in order of how reactive they are.

    Lists from most reactive to least reactive: potassium, sodium, calcium, magnesium, aluminium, zinc, iron, tin, lead, copper, silver, gold, platinum
    The reactivity series for some metals

    Magnesium and zinc are often used as sacrificial metals. They are more reactive than iron and lose their electrons in preference to iron.

    Although tin is used to coat steel cans, it does not act as a sacrificial metal. Instead, it acts only as a barrier to stop air and water reaching the surface of the iron or steel. The tin layer may actually make rusting happen faster if it gets scratched, because then iron loses electrons in preference to tin.

    Rust is irreversible because the iron and oxygen have combined on an atomic level creating the compound iron oxide and you would need to manipulate it on the atomic level to separate it.



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  4. Rusting happens by a chemical reaction with moisture, oxegan and water. It can be prevented if you coat the metal with a bit of zinc. Rusting is irreversible because it has all ready weakened th metal and has made cracks .

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  5. Iron and steel rust when they come into contact with water and oxygen. Both water and oxygen are needed for rusting to occur in a experiment.21 per cent of the air is oxygen.nail does not rust when air or water is not present.Rust can be a minor annoyance if it stains your clothing or your tools, or it can be a major disaster in buildings and infrastructure.To prevent rust apply oil in order to provide an insulation layer between air. rust is irreversable because the iron and oxygen have combined on an atomic level creating the compound iron oxide.

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  6. Rusting happens in 48 hours or 2 also 1.Rust is an iron oxide, usually red oxide formed by the red ox reaction of iron and oxygen in the presence of water or air moisture.Sometimes rust spread all around the world,specially the rust only rusts on iron.Rust is made out of iron and oxygen.

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  7. Iron and steel rust when water and oxygen contacts with each other. Water and oxygen are both needed to occur rusting. To prevent rusting you can coat things with:
    - Oil
    - Petroleum jelly
    - Varnish
    - Zinc
    - Paint
    - Oil based paint

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  8. Rusting occurs when water, oxygen and metal make a chemical reaction which is commonly called rust. Let's say its your car that starts to rust. First of all, the rust starts to seep through the paint of the car and goes further into the metal, creating a crack in your car and leaving your car all brown-rusty.

    Thankfully, rusting can be prevented. According to resent studies from 5JM, the worlds bests scientists, the best substance for preventing rusting is varnish closely followed by petroleum jelly (Vaseline,) then oil based paint. Just coating your garden lock, drain pipe or bicycle in one of these is sure to prevent rusting for up to several years.

    Sadly, rusting is an irreversible change and can not be removed once it has spread. This is because, rusting turns objects brow and covers things in a layer of lumpy brown stuff. Although the brow layer can be removed the object is then permanently stained brow.

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  9. Iron and steel cause rusting when they have been touched by or come into contact with water or oxygen. Aluminium on the other hand does not corrode (rust) easily. Rust is an iron oxide, usually formed by the reaction of iron and oxygen. There are several ways of preventing iron and steel rusting. Some of these work because they stop oxygen or water reaching the surface of the metal. Here are some examples:
    - Oiling - bicycle chains.
    - Greasing - for example nuts and bolts.
    - painting - for example car body panels.

    Iron and steel objects might also be covered with a layer of metal. Food cans for example, are covered in a layer of tin.

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    Replies
    1. Iron and steel rust happens when they come into contact with water and oxygen. Both water and oxygen are needed for rusting to occur.

      some things that you can use in school are -

      varnish-

      petroleum jelly-

      paint-

      Delete
  10. Rusting occurs when water, oxygen and metal make a chemical reaction which is commonly called rust. Let's say its your car that starts to rust. First of all, the rust starts to seep through the paint of the car and goes further into the metal, creating a crack in your car and leaving your car all brown-rusty.

    To prevent you can coat this with:
    *Oil
    *Zinc
    *Petroleum jelly
    *Varnish
    *Paint
    *Oil based paint.

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  11. Iron and steel cause rusting when they have been touched by water or oxygen. On the other hand does not rust easily. Rusting is a irreversible change because you can not change it back ,you can only prevent rusting. Galvernising is a fantastic technique to prevent rusting. Galvernising is when you use another material that does not rust for example Zinc.

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  12. Rusting is known as a chemical reaction were water (which is known scientifically as H2O) reacts with air. 5JM have recently discovered things which can prevent rusting, for example:
    -oiling your bike,
    -oiling your nails, bolts, nuts ext
    -and scrubbing your pots and pans.
    Apparently rusting is irreversible and therefore cannot be removed.

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  13. Rusting is a chemical Reaction. 5JM had found out that the best to rust out of Oil, Water, Coca cola and Milk was the Water because Water has Oxygen in it and water is really fast to rust.

    Does Rust

    1. Water
    2. Steal
    3. Metal
    4. Bike
    5. Scooter
    6. Pans
    7. Nail
    8. Bike Lockers

    Doesn't Rust

    1. Paint
    2. Oil
    3. Milk
    4. Coca cola
    5. Pepsi
    6. Copper
    7. Zinc
    8. Petroleum Jelly ( Vaseline )

    I have given Examples of which materials will rust and which won't.

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  14. There are 3 types of ways to prevent rusting. There is greasing oiling and painting. The differance of oiling and greasing is that greasing is a semi-solid and oiling is a liquid. Rusting occurs when oxygen and water and is mixed and causes a chemical reaction. This reaction is called oxydation. Rusting appears when it rains alot.Rust is the common name for iron oxide, which as the name implies, is made up of the elements iron and oxygen. The compound is Fe2O3. Iron combines quickly with oxygen, and the process of turning iron to iron oxide is an example of corrosion. You can see things like steel rust because steel contains iron.

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