It allows heat to travel through it easily.
Yes, that is what "good thermal conductor" means.
No, krypton is not a good thermal conductor. It is a noble gas and has very low thermal conductivity compared to other materials.
steel
No, potassium is not a good thermal conductor compared to other materials. It has a relatively low thermal conductivity, meaning it is not efficient at transferring heat.
Astatine is not a good thermal conductor. It is a poor conductor of heat due to its low thermal conductivity, similar to other halogens. This makes astatine a relatively inefficient material for transferring heat.
Galena is not a good conductor of electricity. However, it is a good conductor of heat due to its high thermal conductivity.
i forget
fabric
No.
Yes, being a metal, aluminum is a good thermal conductor.
Copper is a good electrical and thermal conductor.
a metal