Question

section 1
explaining marble changes in the taj mahal by openscied
the taj mahal was built in agra, india by the emperor shah jahan as a memorial for his wife. it
was completed around 1653. it is an impressive building created out of white marble.
however, in the last 50 years, people have noticed that the building is turning from white to
yellow and the marble is cracking and falling apart.
the marble used to build the taj mahal is made mostly of one substance: calcium carbonate.
scientists suspect that chemical reactions between a substance that is coming into contact
with the calcium carbonate in the marble might be causing it to break down.
here are two possibilities that are causing the change in color (yellowing), cracking and fallin
apart:
2
scientists suspect that chemical reactions between _ and a substance
is causing the marble to break down.
(a)
calcium carbonate
calcium sulfate
calcium nitrate
carbon dioxide
(b) the acid rain is caused by certain pollutants in the air. which image below shows how the
molecules in acid rain move?

Explanation:

• For part (a), the text clearly states that the marble of the Taj Mahal is made mostly of calcium carbonate, and the reaction is between calcium carbonate and another substance.
• For part (b), since the question is not fully clear about the options (only one image - option A is shown partially), but assuming standard knowledge about acid - rain (which is a liquid, and in liquids, molecules are close together but can move around each other).

Answer:

(a) A. Calcium Carbonate
(b) (Assuming the correct molecular movement for a liquid - like acid rain, if the shown image (option A) represents molecules close together with some movement (vibrations and translations) as in a liquid) A.