One hot thing

Right!

Once the staves are put into the water, to top in the water takes on the temperature of the hot water. Within the stave the heat is transportet from the area of the highest temperature to thea area of the lowest temperature. Metal can transport heat the best. Therefore, the metal stave heats up at the top the fastest. The other three materials are very bad heat conductors. Thery thermal conductive characteristics are much lower than those of metal. Thus, the other staves need more time until their tops are noticably warmer.

Of course, you can try this at home. Use objects that are of equal size but different material. (e.g. spoons made of plastic, wood, metal...)
Be careful!!!
Working with hot water can be dangerous. Please make sure not to touch the hot water because you might burn yourself. You can always ask an adult for help.