启航班 张思远 张奥伦 林明恩 郑雯磷

1. BSC Science Project 启航班 张思远 张奥伦 林明恩 郑雯磷

2. Background History: The stone slabs of the pavement are ordered to be build in the Qing Dynasty by the last emperor of China, Pu Yi. These stone slabs have not been renovated since then and remains just as they were more than a 100 years ago.

3. Science Adaptations: • 1. There are tiny gaps between each slab of stone on the pavement. This is to leave space for the stone slabs to expand and contract without cracking in extreme temperatures. • At extremely high temperatures, the stone slabs gain thermal energy. The atoms that make up the stone gain kinetic energy and vibrate and collide with each other more frequently and vigorously. This results in greater inter-atomic spaces between each stone atom. This causes the overall expansion of the stone slabs. By leaving gaps and spaces between each stone slab, the stone slabs can expand at high temperatures without cracking or breaking.

4. Background History: This is the palace where the past Emperors conduct their state affairs with the state officials. It was most recently renovated by the Chinese government in 2008 for tourists visiting China during the Beijing Olympics.

5. 2. The palace has roofs slanting down and does not have flat roofs. This is to ensure that rain and snow flows down the roof easily and does not accumulate on the roof. When rain or snow accumulates of the roof, this will increase the total weight of the roof and the weight each pillar has to support. This may create a situation whereby the accumulating rain and snow makes the roof too heavy, causing the roof to collapse.

6. 3. Roof is made of many single tiles fit together. This makes construction and repair of roof easy as the tiles that are damaged can be replaced individually instead of replacing the whole roof. Furthermore, the many single tiles increases the total surface area of the roof exposed to Sunlight, increasing internal heating from sunlight. • 4. There are lightning protection wires installed on the top of the roof so that they will attract lightning, conducting lightning away and preventing it from striking and damaging the Palace.

7. Background History: This photograph depicts part of the palace walls. It shows how the palace walls last renovated 100 years ago have been corroded and damaged due to weathering and the acid rain.

8. 5. Carbon dioxide in the air dissolves in the rainwater, forming carbonic acid. This makes the rainwater slightly acidic. • Furthermore, due to the large amounts of factories and motor vehicles in Beijing, large amounts of sulfur dioxide gas is released into the air. Sulfur dioxide with dissolve in rainwater to form sulfurous acid. Sulfurous acid will then oxidize in the air to form sulfuric acid. This results in the formation of acid rain. • Since the palace walls are made of stone, they made contain some limestone(calcium carbonate). As an acid will react with a carbonate to form a salt, carbon dioxide and water. • The acid rain (Sulfuric acid) will react with the limestone (Calcium carbonate) present in the palace walls to form Calcium Sulfate, Carbon dioxide and Water. This results in the wall being corroded as seen from the photograph. • H2SO4 + CaCO3  CaSO4 + H2O + CO2

9. Background History: This photograph depicts the roof structure of the Tai Ping Palace. (Notice the netting) • There are nets surrounding the area under the roofs of the Palace.

10. The story goes that in the Qing dynasty, the Mongolians worshipped the crows and fed them daily. The crows have since developed a habit and will visit the palace everyday. To prevent crows and birds from building their nests under the roof and damaging the structure of the palace, nets are installed to prevent the birds from entering the roofs.