Additional SEE Practice — Q3. When a person puts a lactometer into milk, the entire narrow stem sinks into the milk. What conclusion can be drawn?

Question

Accepted Answer

A lactometer sinks more when the density of the liquid is low, and floats higher when the density is high. Since the entire stem sinks, it means the milk has a lower density than pure milk should have. This suggests that the milk may have been mixed with water, since water has a lower density than milk and would reduce the overall density of the mixture.