explain what causes the wire to resist the flow of thecurrent?

I don't think the above explanations are what you want. Fundamentally, resistance is mostly because conduction electrons scatter off of lattice vibrations in the metal. "Lattice vibrations" just means that heat in the wire causes the "blocks" that make up its crystal structure to be a little out of place. When electron waves hit blocks that are out of place, they bounce around and dissipate heat. You can actually eliminate most resistance by lowering the temperature of your wire. In some materials, this can even remove ALL the resistance and such materials are called super-conducting (assuming they have another specific property that doesn't matter here). The other source of resistance in a wire (much smaller) is the scattering of conduction band electrons off of impurities in the wire (such as atoms of another element).

The ticker the wire the greater the current flow with out heating the wire has resistance also there is a magnetic field around the wire which causes a back EMF which is called reluctance.The greatest molecular flow is on the out side of the wire if you could test for curent flow at the very center of the wire it should be zero

That is why HT pylons wires are made of two different metals the out sideas a conductor and the inside for strength.

Basically the electrons in the wire are not very firmly fixed to their individual atoms and so they form a kind of "soup" which can flow between the large nuclei of the metal atoms. When there are too many electrons in one area of the wire, they try to flow to a less negative (less crowded with electrons) area. As they try to move, most of them can go straight between the nuclei but some will hit a nucleus and bounce back, which slows the average speed at which they travel through the wire.

basically when a wire conducts the free electrons move around the wire, this causes heat which uses energy and therefore leaves less to move the electrons - this is effectively the resistance.

First, we have to know how wires conduct electricity:

assume the current is going from left to right,

when current is applied, atoms at the left side tend to give some of its electrons to the adjacent atoms to its right and take the same number of electrons from the conductor to the left,

the atoms which took the electrons from the first atoms will give some of their electrons to the adjacent atoms to the right before they take those electrons,

and this process continues to the right until the last atoms to the right give up some of their electrons to the conductor to the right and replace them with the electrons they take from the atoms to their left.

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different materials have different tendencies to exchange their electrons, the higher the tendency, the higher the conductivity of that metal,

and vice verse,

the lower the tendency to exchange the electrons the lower the conductivity of that metal, and thus the higher the resistance of that metal

a certain size of wire can pass a certain amount of current, increase the flow, and you increase the temperature, increase the gauge of the wire and it will pass more current and stay cold

there are only so many electrons in a given gauge,

The bigger the gauge etc.

Regards

Brian

diffrent types of metal do different things, like tungsten when current flows throw it lights up(used in lightbulbs) or at least i think its tungsten and i think its how compact the atoms are.