The descriptions below explain two ways that water is used by plants on a sunny day.

Question

I. In a process called transpiration, some liquid water in leaves changes to water vapor. The water vapor is released into the air through tiny pores in the leaves. This allows more liquid water from the soil to be pulled up the roots and stem to replace water lost from the leaves.

II. Plants use some of this water in leaves in a process called photosynthesis. During photosynthesis, water and carbon dioxide break apart and recombine to form two new substances, oxygen and glucose.

Based on the above description of transpiration and photosynthesis, which type of change happens to water during each process?

In transpiration, because some of its properties change, water undergoes a physical change but keeps its identity. In photosynthesis, because its identity changes, water undergoes a chemical change.
In transpiration, because some of its properties change, water undergoes a chemical change but keeps its identity. In photosynthesis, because its identity changes, water undergoes a physical change.
In transpiration, because its physical properties change, water undergoes a physical change and loses its identity. In photosynthesis, because it keeps its identity, water undergoes a chemical change.
In transpiration, because its chemical properties change, water undergoes a chemical change and loses its identity. In photosynthesis, because it keeps its identity, water undergoes a physical change.
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Answer 1

The correct understanding of the changes that happen to water during transpiration and photosynthesis is as follows:

1. Transpiration is a process where liquid water changes to water vapor. This is a physical change because the water retains its chemical identity (H₂O) even though its state changes from liquid to gas.

2. Photosynthesis involves water breaking apart and recombining with carbon dioxide to form new substances (oxygen and glucose). This process alters the chemical identity of the water, indicating that it undergoes a chemical change.

Based on this explanation, the correct statement would be:

In transpiration, because some of its properties change, water undergoes a physical change but keeps its identity. In photosynthesis, because its identity changes, water undergoes a chemical change.