Metal atoms can bond together to form a giant structure, which is held together by metallic bonds; this means that there are many free electrons in these structures. This is because the metal atoms in the metallic structure have electrons on the outer-most shell that pass freely from one atom to another; these electrons can carry heat from one metal atom to another (making metals good conductors of heat). The electrons in these metal structures can be ‘pushed’ in one direction buy a lack of electrons or a abundance of electrons in one area, as the electrons flow through the metal a current and electricity is produced.
The current is therefore, the speed at which the electrons flow through a circuit and the voltage is the driving force that pushes the electrons (usually provided by a cell). However, despite that the fact that metals are good conductors of electricity they all have a certain resistance against the flow of electrons. This means that despite the driving force/voltage the speed at which the electrons flow through a circuit (ampage) is reduced. These properties can be affected by their surroundings, the five factors that can affect metals are; heat, radiation, a magnetic field and the flow of electrons/ current.
In a circuit, the resistance is affected by these factors, the resistivity of the material used and the width and length of the wire used in the circuit. The reason that the length or width of the wire affects the resistance without changing the physical properties of the metal is that, the smaller the width the less room there is for the electrons to flow through the wire. And that the longer the wire the more likely the individual electrons are to hit a positive ion and lose it’s energy. This means that the resistance is proportional to the object’s resistivity and length, and inversely proportional to its cross-sectional area.
The temperature affects the resistance of the wire by changing it’s properties; a rise in temperature makes the individual atoms vibrate in the giant structure (if there is enough heat the individual atoms can break off from the giant structure, consequently making the metal turn into a liquid or gas). As the individual positive ions vibrate they get in the way of electrons and slow them down, the vibrations often blocks the passage for some electrons. Therefore with an increased amount of heat the positive ions vibrate more causing more electrons to be blocked from going further, the vibrating causes resistance.
Therefore with an increase in the temperature, there is an increase in the vibrations and there is an increase in the resistance. This means that an increase in the temperature will mean an increase in the resistance, and a decrease in the temperature will decrease the resistance. This means that the resistance is directly proportional to the temperature in the formula: Resistance ? k*the temperature (where k = the gradient). The results show me that the temperature is inversely proportional to the resistance, which goes against my prediction and against the theory behind this relationship.
I can conclude this as although the results do not show any immediate patterns, both the linear and the logarithmic treadlines have a negative gradient (are sloping downwards). This means that I can classify the results as having a very weak negative correlation, according to these results, the higher the temperature the lower the resistance and the lower the temperature the higher the resistance. From these results I cannot identify whether the very weak correlation is logarithmic or linear, as the results do not show any distinctive patterns.
However if I follow the theory behind this correlation (ignoring the fact that these results show the opposite of what the theory predicts), it tends to suggest that the relationship is linear (y=mx + c not y=nx^2 + mx +c). Therefore according to this theory, the relationship is linear, therefore according to the linear treadline the relationship is y = -0. 0238x + 49. 577 namely Ohms = -0. 0283the temperature + 49. 577. I have used the treadline as a basis for this conclusion because the results have a weak correlation, and the linear treadline is therefore nearer to the theoretical result.