A beaker of freshly boiled water sits on the bench. What is the hazard?

• It is see-through
• It could scald skin
• It is round

Which of these is a hazard in an experiment with a lit candle?

• The flame could burn skin
• The candle is yellow
• The candle smells like wax

A hazard and a risk mean exactly the same thing.

Circle one:   True   False

Before heating a test tube of liquid over a flame, what is the most sensible precaution?

• Heat it as fast as possible to save time
• Point the open end away from people
• Hold the tube with bare fingers near the flame

One student holds a lit match for one second; another holds it for ten seconds. Whose risk is bigger?

• The one holding it for one second
• Both risks are exactly the same
• The one holding it for ten seconds

A student plans to mix bleach and vinegar in a closed jar. What hazard matters most here?

• The jar might change color
• The liquid might taste sour
• The mix could give off a harmful gas

A plan calls for testing eggshells with a large amount of mild acid. How could the student lower the risk?

• Use double the acid to see a bigger reaction
• Skip goggles since the acid is only mild
• Use less acid and wear goggles

Marcus says wearing goggles makes an experiment completely risk-free. What is wrong with his thinking?

• Goggles are uncomfortable so nobody should wear them
• Burns and spills are still possible
• Risk only matters if you are not wearing safety gear