Answer:
Aluminum had more value than gold in the 1820s, because it was harder to obtain. Hope this helped :)
Warmer air is less dense than cold air.As air warm it rises while the cold air sink. Warmer air masses forces the cooler air to move which causes wind. These is illustrated when you open a hot oven the hotter air inside the oven rises into cooler air outside the oven.
Separation will be achieved if one component adheres to the stationary phase more than the other component does.
