启航班
张思远
张奥伦
林明恩
郑雯磷

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.
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.

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.

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.

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.

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.





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


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.

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.