Researchers are investigating how perfluoroalkyl substances accumulate in the food chain.

The laboratory was shut down after inspectors discovered an unregistered controlled substance stored without proper documentation.

The chemists carefully measured the amounts of substance in each sample before proceeding with the experiment.

To determine the amount of substance in the sample, the chemist measured the number of moles of the solute present.

In determining the constitutionality of the statute, the court focused on the pith and substance of the law rather than its incidental effects.

When a minnow is injured, the alarm substance released from its skin causes nearby fish to flee.

After losing his job, he struggled with substance abuse before finding help.

The lab identified a rare chemical substance that could revolutionize battery technology.

During the inflammatory response, substance P is released from sensory neurons and amplifies pain signaling.

The laboratory confirmed that the sample was an elementary substance composed solely of hydrogen molecules.