States of Matter/Phases
Which state of matter has the most kinetic energy?
Gas
What is distillation used for?
To separate mixtures using boiling points.
What is the boiling point of water? (Bonus points if you know the temperature in Fahrenheit!)
100 °C (212 °F)
What is a mixture?
Two or more things combined, not chemically
What is the process where a solid changes directly into a gas?
Sublimation
Two liquids don’t mix and form layers. Which one is on top and why?
The one with lower density is on top
What is the difference between boiling and melting?
Boiling = liquid to gas; Melting = solid to liquid
Is salt water a pure substance or mixture?
Mixture
Name a real-life example of deposition.
Frost on surfaces like windows or grass.
A 50g object occupies 25cm³. Will it sink or float in water?
Sink, density is 2g/cm³
If a substance melts at 80°C and boils at 150°C, what state is it at 100°C?
Liquid
True or False: Tap water is not considered pure water.
True
What is the process where a solid changes directly into a liquid?
Melting (Fusion)
Why does heating a substance often lower its density?
Particles spread out, increasing volume
Two liquids boil at 78°C and 100°C. Which one will evaporate faster at room temperature, and why?
The one that boils at 78°C—it has weaker intermolecular forces and evaporates more easily.
Name a separation technique besides distillation.
Filtration, magnetism, chromatography, solubility,
A scientist cools a gas until it becomes a solid. What two phase changes occurred?
Condensation followed by freezing.
Why can we use distillation to separate water and salt?
Water boils, salt doesn’t
Explain how pressure affects the boiling point of a liquid using an example.
At high altitudes, air pressure is lower, so water boils below 100°C—e.g., in the mountains.
Explain why filtering cannot separate a sugar solution, but distillation can.
Sugar is dissolved in water, not suspended; distillation separates by boiling point.