Bilal is learning about the branches of chemistry. His teacher explains that green chemistry focuses on designing products and processes that minimize environmental harm. Which of the following activities is an example of green chemistry?

Chloe reads that a certain state of matter has no fixed shape or volume and particles are far apart with very weak forces. She observes helium gas in a balloon. What state of matter is helium in the balloon?

Suspension particles:

Graphite is an allotrope of:

George is learning about the compressibility of states of matter. He knows that gases are highly compressible, liquids are almost incompressible, and solids are incompressible. Which state of matter has particles that are closest together?

Graphite is an allotrope of:

Plasma is mainly found in:

David has a container of air. He knows that air is a mixture of gases like nitrogen and oxygen. Based on the states of matter, what is air classified as?

Khalid is studying how chemistry is used in forensic science. He learns that analytical chemistry is used to analyze evidence. Which of the following techniques is used in forensic chemistry?

Ming is preparing a concentrated solution of sodium chloride. He adds more solute to the solvent. How does the concentration of the solution change?