It's Aluminium, but I'm not sure why sorry.

aluminium because its liek structured from a metal which is like erm.......easyily affected by heat?

The answer is Aluminium..and it's to do with the molecular bonding...think Aluminium is co-valently bonded and Brass isn't..look it up..rpetty sure it's something like that though

The bonding in elemental aluminium is metallic. Each aluminium atom loses an electron (therefore becoming an ion) and all the electrons that have been lost surround the positive Aluminium ions holding them together.

What normally happens when you heat up a solid is that the atoms/ions vibrate more. How well a material conducts heat depends on how well the atoms/ions can pass those vibrations along. Metals do this quite well, and the electrons also help to pass on the energy, which makes metals very good conductors.

Aluminium and copper (one of the two metals in brass) both have the same lattice structure. The ions are packed as close as is possible. Zinc (the other metal that makes up brass) adopts a slightly different structure, where the ions are not packed quite as closely. I imagine that how close the ions/atoms in a structure are to each other plays a large part in the conductivity, so this might explain why aluminium is better at conducting heat that brass.

Don't quote me on that though, 'cos physics was never my strong point!

I'd have thought brass was a better conductor because the molecules in it are packed closer together (it's more dense)...but that's my twisted and most probably wrong thinking

That's the answer..because Brass is an alloy(made up of more than one metal) it is harder to get the molecules to vibrate because they are packed together so tightly...i could be totally wrong although I did get a C in Higher Chemistry