Question

In 2-3 sentences, in your own words, describe why you chose that type of change in the previous question. Key points you may include in your response:

The definition of physical/chemical change
The start/end products in a physical/chemical change
The start/end appearance in a physical/chemical change
The particular evidence observed to indicate a physical/chemical change.

Answer 1

I chose a chemical change because it involves the transformation of substances into new products, which alters their chemical compositions. For example, when iron rusts, the original metallic appearance of iron changes to a reddish-brown powder, indicating a chemical reaction has occurred, evidenced by the release of heat and change in color. In contrast, a physical change, such as melting ice, does not alter the substance's chemical identity; the water remains H2O in both its solid and liquid forms.