Question

which is an example of making a qualitative observation?
○ measuring the speed of the chemical reaction
○ describing how copper changes color in chlorine
○ recording how long it takes to burn magnesium
○ showing the results of an experiment with a graph

Explanation:

Qualitative observations are descriptive and non - numerical, focusing on qualities like color, texture, etc.

• "Measuring the speed of the chemical reaction" involves a numerical measurement (speed), so it's quantitative.
• "Describing how copper changes color in chlorine" describes the quality (color change) of the reaction, which is qualitative.
• "Recording how long it takes to burn magnesium" involves a numerical measurement (time), so it's quantitative.
• "Showing the results of an experiment with a graph" is a way to present data, not an observation type.

Answer:

B. describing how copper changes color in chlorine