Question

question 1 of 5
a student hypothesizes that the bubbles on this water plant are oxygen gas
$(o_{2})$. however, identifying a gas as $o_{2}$ with direct evidence requires many
kinds of equipment.
which observation would provide indirect evidence that the bubbles are not
$o_{2}$?
a. the production of bubbles by the plant when it is in darkness
b. a change in the size of the plants leaves over time
c. a description of the color and shape of the plants leaves
d. the estimated volume of all bubbles produced by the plant

Explanation:

Plants produce oxygen (\(O_2\)) through photosynthesis, which requires light. If bubbles are produced in darkness, it contradicts the known process of \(O_2\) production via photosynthesis (since photosynthesis can't occur without light), thus providing indirect evidence that the bubbles are not \(O_2\). A change in leaf size (B) relates to growth, not gas identity. A description of leaf color and shape (C) is about plant morphology, not gas. Estimated bubble volume (D) gives no info on gas type.

Answer:

A. The production of bubbles by the plant when it is in darkness