A student wants to know if a clear liquid is pure water or saltwater. Which test best distinguishes them using physical properties?

Oil and water form two layers. Which property allows you to separate them by pouring off the top layer?

Unopened carbonated water (CO₂ dissolved in water) is:

A material that always boils at exactly 100 °C at standard pressure is most likely a:

Which is a pure substance?

A teacher mixes two solutions at room temperature. The cup becomes noticeably warmer and remains cloudy with tiny solid particles. What two pieces of evidence indicate a chemical change?

A student mixes vinegar with baking soda in a zip bag. The bag inflates. What is the best evidence a chemical change occurred?

Which observation during candle use is a chemical change?

A student drops an effervescent tablet into water. The mixture fizzes vigorously. What is the evidence of a chemical change?

Apple slices turn brown after sitting out. What evidence points to a chemical change?