Join TSR now and get all your revision questions answeredSign up now

AQA GCSE - Unit 3 (P3,B3,C3) New specification papers. Watch

    Offline

    0
    ReputationRep:
    Veins take blood from the organs to the heart
    arteries take blood from the heart to the organs
    and capillaries allow substances needed by cells to be passed out of blood and substances produced by cells passes into blood
    Offline

    3
    ReputationRep:
    Hey lolface, lets test each other on physics and chemistry today, there was enough biology yesterday.

    In answer to your question an ester is made by reacting a carboxylic acid + alcohol --> ester + water
    You use a acidic catalyst to speed up the reaction usually, sulfuric
    Offline

    3
    ReputationRep:
    How do transformers work?

    and what does/is a step up and step down transformer and what do they do with the voltage (pd)
    Offline

    3
    ReputationRep:
    (Original post by cycahm)
    Veins take blood from the organs to the heart
    arteries take blood from the heart to the organs
    and capillaries allow substances needed by cells to be passed out of blood and substances produced by cells passes into blood
    correct! well done, capillaries are used for diffusion, you mentioned what happens, just make sure you say its diffusion .

    Explain how stents work and say what they are :rolleyes:
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    How do transformers work?

    and what does/is a step up and step down transformer and what do they do with the voltage (pd)
    I'll try and balance the both of you :eek:

    A transformer works by electromagnetic induction. Here, a alternating current is passed over the primary coil which means that the magnetic field keeps changing, this change is felt by the soft core which then passes it on to the secondary coil. The changing field creates a potential difference across the secondary coil.

    Why would a DC current not work in a transformer?
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    correct! well done, capillaries are used for diffusion, you mentioned what happens, just make sure you say its diffusion .

    Explain how stents work and say what they are :rolleyes:
    theyre small mesh tubes inserted by surgeons when your arteries begin to narrow to keep them open
    sorry you guys should do p3 and c3 ill come back when ive revised
    Offline

    0
    ReputationRep:
    (Original post by lolface32)
    You got some catching up to do, but C3 and P3 can catch on quick so dw!

    Explain the purposes of the veins, arteries, capillaries?
    Veins = Carry blood to the heart. Usually carries deoxynentaged blood.
    Arteries = Carry blood away from the heart. Usually caries oxygenated blood
    Capillaries = Provides a blood supply to cells. Carries oxygenated and deoxygenated blood.
    Offline

    3
    ReputationRep:
    (Original post by lolface32)
    I'll try and balance the both of you :eek:

    A transformer works by electromagnetic induction. Here, a alternating current is passed over the primary coil which means that the magnetic field keeps changing, this change is felt by the soft core which then passes it on to the secondary coil. The changing field creates a potential difference across the secondary coil.

    Why would a DC current not work in a transformer?
    Correct well done, urm, Voltage in a transformer is developed only with a frequency. Since a dc supply has a zero frequency, voltage in a transformer will remain zero also. They don't change their current
    Offline

    3
    ReputationRep:
    (Original post by cycahm)
    theyre small mesh tubes inserted by surgeons when your arteries begin to narrow to keep them open
    sorry you guys should do p3 and c3 ill come back when ive revised
    Some C3:

    Part 1:

    1)Describe some characteristics of the transition elements.
    2)What causes hard water? State the two types of hard water.
    3)Explain how boiling removes temporary hardness.
    4)Describe how an ion exchange resin works.
    5)When Bromine reacts with Sodium Iodide, the bromine displaces the iodine to form Sodium Bromide + Iodine. Explain in terms of the electronic structure of the Halogens, why this occurs.
    6)What type of ions to the halogens form?
    7)Describe the trends shown in group 7 as you move down it.
    8)Write a balanced symbol equation for the thermal decomposition of calcium hydrogencarbonate in a kettle.
    9)Describe some uses of transition metals.

    Hopefully they make sense/are do-able :P

    Enjoy.
    Offline

    3
    ReputationRep:
    What is the motor effect? and how does it work?
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    Correct well done, urm, Voltage in a transformer is developed only with a frequency. Since a dc supply has a zero frequency, voltage in a transformer will remain zero also. They don't change their current
    Well, you were going the right way but, you could have also mentioned electro magnetic induction, and how if the magnetic field won't keep changing, there won't be any of it!
    Offline

    3
    ReputationRep:
    (Original post by lolface32)
    Well, you were going the right way but, you could have also mentioned electro magnetic induction, and how if the magnetic field won't keep changing, there won't be any of it!
    LOL FAIL :cool:, ahaha
    Offline

    3
    ReputationRep:
    Swiftly moving on.... explain why the haber process is made effeicent in producing a high yield (3 marks)
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    What is the motor effect? and how does it work?
    The motor effect is when a force is experience on a wire carrying current in a magnetic field.
    I don't get the second question?
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    LOL FAIL :cool:, ahaha
    Like a baws
    Offline

    3
    ReputationRep:
    (Original post by lolface32)
    Like a baws
    ahaha you know , explain the process of filtering water to make it safe to drink. How you make it clean
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    ahaha you know , explain the process of filtering water to make it safe to drink. How you make it clean
    Pass it through a mesh screen to remove sticks etc..
    Then add chemicals to make solids and microbes stick to each other and fall to the bottom, it is then filtered to remove the solids. Finally chloride is added to the water to kill of bacteria.

    Or you can just buy a ion exchange resin, which will exchange magnesium and calcium ions in a exchange for another ion.
    Offline

    0
    ReputationRep:
    Give the advantages/ Dis-advantages of ultrasound, and also the uses! Don't bother describing
    Offline

    3
    ReputationRep:
    Advantages: it produces a highly detailed image, which is 3D, ultrasound is not ionising therefore it is safe, Ultrasound scanning is noninvasive (no needles or injections) and is usually painless., Ultrasound is widely available, easy-to-use and less expensive than other imaging methods and it can distinguish between types of tissue.

    Disadvantages: its expensive, not readily availiable, cannot sometimes detect some cancers

    Uses: fetus check ups, removal of kidney stones
    Offline

    3
    ReputationRep:
    Explain what is total internal reflection, and state its uses
 
 
 
Poll
Which web browser do you use?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.