# Resistance the wire/conductor is made out of.

Resistance is a “property/characteristic” of any material and it’s the term used to describe how materials oppose the flow of current through it when a potential difference is applied across it. So imagine the electrons in electricity move along the wire they collide with ions much larger in size compared to the electrons, these collisions will resist the flow of electrons. So resistance is the measure of how difficult it is for a current to flow.  Every material to some extent prevents a smooth flow of electrons through it due to said ‘ lattice collisions’. And this opposition is naturally offered by every material, however there’s a resistance to the flow of electric current in most conductors. Copper for example is considered a good conductor of electricity because it offers a very small opposition to the flow of electrons, since the resistance is so low the metal allows less moving electrons to collide with the ions in the metal so there is reduced opposition. Resistance is given the symbol R and has the unit symbol ? (which is a Greek letter omega and pronounced ‘ohm’)However there are 4 factors/variables that can affect the resistance of a wire/conductor this are; length of the conductor, the area of cross-section of the conductor, the nature of the conductor and the temperature of the conductor/wire. Length of a conductor: Resistance is directly proportional to length as when the length of the conductor increases the electrons experience more collisions while traveling from one end to the other inside the conductor. Hence the resistance of the conductor increases with the increase of the length of the conductor. So more collisions (due to the length of material) ? larger R. Example diagram is below showing the relationship between resistance and length…Nature of the wire/material: The resistance of a wire/conductor also depends on what material the wire/conductor is made out of. The electronic configuration of the atoms in the material determines how much resistance/opposition the material offers to the flow of current going through it. For example if the outermost shell in an atom is almost full the atom is less likely to allow electrons to wander this type of material is most likely an  insulator. However is the outermost shell is less than half full then the atom will more likely let electrons wander this type of material is most likely a conductor. Overall the harder an electron holds onto its electrons the harder it will be for a current to flow through it. To show this your graph for this would be a bar chart not a line graph.Temperature of the wire/material: Resistance increases with the increase of temperature in the wire, a hotter wire will have a larger resistance because increasing the temperature of a wire means the ions in that wire will receive more heat energy which transfers to kinetic energy thus the ions vibrate more this increase in vibration then leads to more collisions between the ions and the electrons – increase in collisions means an increase in resistance to the flow of electrons (current).  The equation below illustrates the relationship between temperature and resistance.