Question

In caves, dripping groundwater containing calcium bicarbonate can form stalactites and stalagmites. When the water is exposed to air, some of the calcium bicarbonate turns into calcium carbonate, which gets deposited on the ground. What makes this process a chemical change?
A. A new substance is formed in this process, which is an important clue to chemical change.
B. A change in state is observed in this process, which is an important clue to chemical change.
C. This process involves separation of dissolved substances, which is an an important clue to chemical change.
D. This process involves dissolving substances together, which is an an important clue to chemical change.
E. This process involves breaking and reshaping of substances, which is an an important clue to chemical change.

Answer 1

Answer:

A. A new substance is formed in this process, which is an important clue to chemical change.

Explanation:

A chemical change occurs when a chemical reaction is taken place, so, a new substance is formed. When a physical change occurs, there is a change only in the state of the substance, there is not formed new substances.  So, in the process given, is formed calcium carbonate from calcium bicarbonate, which is a new substance, and a clue that a chemical change happened.

Answer 2

The right answer for the question that is being asked and shown above is that: "E. This process involves breaking and reshaping of substances, which is an an important clue to chemical change." The process of a chemical change is that it involves breaking and reshaping of substances, which is an an important clue to chemical change.